A strong dietary flavonoid known for its anti-inflammatory, antioxidant, and newly discovered anti-cancer effects, quercetin (QR) has important effects on both plant defense systems and human health. For nutritional assessment, its quantitative detection is essential. For that we designed the Bi2S3@ZnO (BSZ) nanocomposite modified glassy carbon electrode (GCE) for this work and showed an excellent electrocatalytic activity towards QR oxidation. This is attributed to the synergistic effect between Bi2S3 and ZnO, which promotes charge transfer and provides an abundant number of active sites. The sensor exhibited an exceptionally wide linear range from 0.1 μM to 3362 μM and an ultra-low detection limit of 0.63 nM. For the accurate determination of QR in various food samples, the practical applicability was successfully demonstrated with excellent recoveries. This study reveals the potential of semiconductor heterojunctions in forward-looking electrochemical sensing systems in addition to establishing an adequate instrument for QR analyzing.
{"title":"Bismuth chalcogenide-Zincite nanocomposite for the determination of a potent bioactive flavonoid","authors":"Hemarani Annadurai , Tse-Wei Chen , Sivaprakash Sengodan , Elayappan Tamilalagan , Shen-Ming Chen","doi":"10.1016/j.flatc.2026.101007","DOIUrl":"10.1016/j.flatc.2026.101007","url":null,"abstract":"<div><div>A strong dietary flavonoid known for its anti-inflammatory, antioxidant, and newly discovered anti-cancer effects, quercetin (QR) has important effects on both plant defense systems and human health. For nutritional assessment, its quantitative detection is essential. For that we designed the Bi<sub>2</sub>S<sub>3</sub>@ZnO (BSZ) nanocomposite modified glassy carbon electrode (GCE) for this work and showed an excellent electrocatalytic activity towards QR oxidation. This is attributed to the synergistic effect between Bi<sub>2</sub>S<sub>3</sub> and ZnO, which promotes charge transfer and provides an abundant number of active sites. The sensor exhibited an exceptionally wide linear range from 0.1 μM to 3362 μM and an ultra-low detection limit of 0.63 nM. For the accurate determination of QR in various food samples, the practical applicability was successfully demonstrated with excellent recoveries. This study reveals the potential of semiconductor heterojunctions in forward-looking electrochemical sensing systems in addition to establishing an adequate instrument for QR analyzing.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101007"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-17DOI: 10.1016/j.flatc.2026.101010
Rimpa Mondal , Sk. Faruque Ahmed , Nillohit Mukherjee
An in-situ electrochemical deposition technique was utilized to develop Co3O4/crystalline graphene (Co3O4/cGr) nanocomposite 2D layered structure on indium oxide (ITO) coated polyethylene terephthalate (PET) flexible structure. Thorough characterizations of the deposited material have been carried out, interestingly that indicated the formation of crystalline graphene in the nanocomposite with an approximate layer count in the graphene stack within 18 and 20 and interlayer spacing of around 0.35 and 0.34 nm. The core-level ionization followed by non-radiative relaxation in Auger spectrum revealed the presence of mixed states of cobalt (i.e., Co(II) and Co(III)) in a spinel oxide structure, whereas, elemental mapping underscored well-distribution of cobalt, oxygen and carbon in the deposited film; that in turn refers to a highly active surface. On the other hand, electrochemical technique for the detection of neurotransmitters like dopamine can be a single-key solution to sensitive, selective and rapid determination of the analyte; where, such unique structural, compositional and surface features of the developed electrode material (Co3O4/cGr) could be well-contributing. Dopamine is a neurotransmitter that plays very important role in regulating human nervous actions and any imbalance in its abundance can cause severe issues like depression, hypertension, Parkinson's diseases and Schizophrenia, to name a few. This makes it very essential to detect the level of dopamine in human serum/plasma with best possible accuracy. So, in this work, the developed Co3O4/cGr nanocomposite was also explored for its possible application as an electrochemical dopamine sensor, and the results in terms of sensitivity, selectivity and reproducibility were quite encouraging.
{"title":"2D layered Co3O4/crystalline graphene nanocomposite: In-situ synthesis, Auger analysis, elemental mapping and fabrication of a flexible dopamine sensor","authors":"Rimpa Mondal , Sk. Faruque Ahmed , Nillohit Mukherjee","doi":"10.1016/j.flatc.2026.101010","DOIUrl":"10.1016/j.flatc.2026.101010","url":null,"abstract":"<div><div>An in-situ electrochemical deposition technique was utilized to develop Co<sub>3</sub>O<sub>4</sub>/crystalline graphene (Co<sub>3</sub>O<sub>4</sub>/cGr) nanocomposite 2D layered structure on indium oxide (ITO) coated polyethylene terephthalate (PET) flexible structure. Thorough characterizations of the deposited material have been carried out, interestingly that indicated the formation of crystalline graphene in the nanocomposite with an approximate layer count in the graphene stack within 18 and 20 and interlayer spacing of around 0.35 and 0.34 nm. The core-level ionization followed by non-radiative relaxation in Auger spectrum revealed the presence of mixed states of cobalt (i.e., Co(II) and Co(III)) in a spinel oxide structure, whereas, elemental mapping underscored well-distribution of cobalt, oxygen and carbon in the deposited film; that in turn refers to a highly active surface. On the other hand, electrochemical technique for the detection of neurotransmitters like dopamine can be a single-key solution to sensitive, selective and rapid determination of the analyte; where, such unique structural, compositional and surface features of the developed electrode material (Co<sub>3</sub>O<sub>4</sub>/cGr) could be well-contributing. Dopamine is a neurotransmitter that plays very important role in regulating human nervous actions and any imbalance in its abundance can cause severe issues like depression, hypertension, Parkinson's diseases and Schizophrenia, to name a few. This makes it very essential to detect the level of dopamine in human serum/plasma with best possible accuracy. So, in this work, the developed Co<sub>3</sub>O<sub>4</sub>/cGr nanocomposite was also explored for its possible application as an electrochemical dopamine sensor, and the results in terms of sensitivity, selectivity and reproducibility were quite encouraging.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101010"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-27DOI: 10.1016/j.flatc.2026.101019
Carlos M. Monzón-Somazzi , Sebastián E. García , Karen E. Navarro-Gamarra , Eduardo M. Patrito
The sulfurization of pre-deposited Mo seed layers is a widely adopted method for synthesizing large-area MoS2 thin films with uniform thickness. However, upon exposure to air, nanometric native oxide films are formed on the Mo surface. Despite the extensive work using thin Mo layers, the oxidation state of the precursor remains poorly characterized. In this study, we investigate the role of Mo precursor oxidation state on MoS2 morphology using 10 nm Mo films on SiO2/Si substrates sulfurized at 900 °C. Pretreatments of the Mo precursor layer included: freshly deposited Mo (having substoichiometric oxides), oxidative aging in air (yielding amorphous MoO3), and reductive annealing in Ar/2% H2 at 450 °C (producing Mo suboxides and MoO2). Scanning electron microscopy revealed the distinct topographies of the resulting MoS2 films: compact granular films from fresh precursors; vertical flakes with voids from aged precursors; and worm-like structures from reduced precursors. Spectroscopic ellipsometry modeling revealed the structure and thickness of the MoS2 films: those prepared from fresh precursors exhibited a compact single-film structure with a thickness of 29.1 nm; films from aged precursors showed a single-film structure interspersed with void regions and a greater thickness of 41.6 nm; in contrast, films from the reduced precursor displayed a double-film structure comprising a compact inner film (12.4 nm thick) and a non-compact outer film (23.1 nm thick). We propose that the sublimation of amorphous MoO3 and its subsequent redeposition as oxythiomolybdate complexes are key to the formation of vertically aligned platelets separated by voids. In experiments where mass transport to the gas phase was suppressed, the resulting MoS2 films exhibited a smooth, compact morphology. MoS2 structures with vertically oriented platelets showed significantly higher electrocatalytic activity for the hydrogen evolution reaction than compact MoS2 films. This study demonstrates that the surface morphology of MoS2 can be precisely controlled by tuning the oxidation state and crystallinity of the Mo precursor.
{"title":"Growth of MoS2 films with vertical flakes via oxidative post-treatment of Mo precursor layers","authors":"Carlos M. Monzón-Somazzi , Sebastián E. García , Karen E. Navarro-Gamarra , Eduardo M. Patrito","doi":"10.1016/j.flatc.2026.101019","DOIUrl":"10.1016/j.flatc.2026.101019","url":null,"abstract":"<div><div>The sulfurization of pre-deposited Mo seed layers is a widely adopted method for synthesizing large-area MoS<sub>2</sub> thin films with uniform thickness. However, upon exposure to air, nanometric native oxide films are formed on the Mo surface. Despite the extensive work using thin Mo layers, the oxidation state of the precursor remains poorly characterized. In this study, we investigate the role of Mo precursor oxidation state on MoS<sub>2</sub> morphology using 10 nm Mo films on SiO<sub>2</sub>/Si substrates sulfurized at 900 °C. Pretreatments of the Mo precursor layer included: freshly deposited Mo (having substoichiometric oxides), oxidative aging in air (yielding amorphous MoO<sub>3</sub>), and reductive annealing in Ar/2% H<sub>2</sub> at 450 °C (producing Mo suboxides and MoO<sub>2</sub>). Scanning electron microscopy revealed the distinct topographies of the resulting MoS<sub>2</sub> films: compact granular films from fresh precursors; vertical flakes with voids from aged precursors; and worm-like structures from reduced precursors. Spectroscopic ellipsometry modeling revealed the structure and thickness of the MoS<sub>2</sub> films: those prepared from fresh precursors exhibited a compact single-film structure with a thickness of 29.1 nm; films from aged precursors showed a single-film structure interspersed with void regions and a greater thickness of 41.6 nm; in contrast, films from the reduced precursor displayed a double-film structure comprising a compact inner film (12.4 nm thick) and a non-compact outer film (23.1 nm thick). We propose that the sublimation of amorphous MoO<sub>3</sub> and its subsequent redeposition as oxythiomolybdate complexes are key to the formation of vertically aligned platelets separated by voids. In experiments where mass transport to the gas phase was suppressed, the resulting MoS<sub>2</sub> films exhibited a smooth, compact morphology. MoS<sub>2</sub> structures with vertically oriented platelets showed significantly higher electrocatalytic activity for the hydrogen evolution reaction than compact MoS<sub>2</sub> films. This study demonstrates that the surface morphology of MoS<sub>2</sub> can be precisely controlled by tuning the oxidation state and crystallinity of the Mo precursor.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101019"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147400102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-18DOI: 10.1016/j.flatc.2026.101012
Rashida Batool , Nazmina Imrose Sonil , Muhammad Ahsaan Bari , Adnan Khalil , Nadeem Raza , Mostafa E. Salem , Muhammad Faizan Nazar , Zaka Ullah
The continuously increasing global demand for sustainable and efficient energy solutions has intensified the interest of researchers in photoelectrochemical (PEC) cells as promising devices for direct solar energy conversion and storage. However, typical PEC systems often bear crucial challenges, particularly limited light absorption, sluggish charge transport, and poor long-term durability. Recent advances in two-dimensional (2D) materials have brought transformative opportunities to meet these limitations owing to their exceptional optical, electronic, and surface features. This review systematically investigates the integration of 2D materials into PEC cells, focusing on their roles as conductive frameworks, interfacial layers, co-catalysts, photoanodes, and photocathodes. A comparative analysis of various 2D materials, including graphene and its derivatives, transition metal dichalcogenides (TMDs), MXenes, black phosphorus, and 2D metal oxides/nitrides, showcases their structure-property-performance relationships. The recent breakthroughs in device performance and emerging strategies, such as heterostructure modulation and defect engineering, have been reviewed and summarized. Furthermore, existing critical challenges, which specifically include material stability, scalability, and charge recombination, as well as proposed future directions involving material discovery, smart PEC systems, and integrated solar-battery schemes, have been overviewed, and their perspectives have been discussed. This comprehensive review aims to provide insights that accelerate the development of next-generation PEC technologies enabled by 2D materials for advanced and smart photo-assisted batteries.
{"title":"2D materials in photoelectrochemical cells: Opportunities for next-generation solar batteries","authors":"Rashida Batool , Nazmina Imrose Sonil , Muhammad Ahsaan Bari , Adnan Khalil , Nadeem Raza , Mostafa E. Salem , Muhammad Faizan Nazar , Zaka Ullah","doi":"10.1016/j.flatc.2026.101012","DOIUrl":"10.1016/j.flatc.2026.101012","url":null,"abstract":"<div><div>The continuously increasing global demand for sustainable and efficient energy solutions has intensified the interest of researchers in photoelectrochemical (PEC) cells as promising devices for direct solar energy conversion and storage. However, typical PEC systems often bear crucial challenges, particularly limited light absorption, sluggish charge transport, and poor long-term durability. Recent advances in two-dimensional (2D) materials have brought transformative opportunities to meet these limitations owing to their exceptional optical, electronic, and surface features. This review systematically investigates the integration of 2D materials into PEC cells, focusing on their roles as conductive frameworks, interfacial layers, co-catalysts, photoanodes, and photocathodes. A comparative analysis of various 2D materials, including graphene and its derivatives, transition metal dichalcogenides (TMDs), MXenes, black phosphorus, and 2D metal oxides/nitrides, showcases their structure-property-performance relationships. The recent breakthroughs in device performance and emerging strategies, such as heterostructure modulation and defect engineering, have been reviewed and summarized. Furthermore, existing critical challenges, which specifically include material stability, scalability, and charge recombination, as well as proposed future directions involving material discovery, smart PEC systems, and integrated solar-battery schemes, have been overviewed, and their perspectives have been discussed. This comprehensive review aims to provide insights that accelerate the development of next-generation PEC technologies enabled by 2D materials for advanced and smart photo-assisted batteries.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101012"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147400104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Na-ion batteries (SIBs) are promising energy storage devices, with graphene derivatives emerging as new anode materials. Chronoamperometry enables precise, mild synthesis of high-quality graphene oxide. Here, chlorine-, sulfur-, and nitrogen-doped graphene oxides (ClGO, SGO, NGO) are fabricated via a simple, straightforward, cost-effective, and ambient-condition method that does not require an inert atmosphere chronoamperometric method and tested as SIB anodes in an ether-based electrolyte. The utilization of diglyme as an electrolyte solvent improved the overall capacity and cycle life of DGO anodes, as diglyme is considered a co-intercalating electrolyte that contributes to the storage of Na+. Morphological analyses reveal that all powders exhibit a two-dimensional structure with uniformly dispersed dopant atoms. The single DGO electrodes show initial discharge capacities of ∼415, 733, and 952 mAh g−1 at 0.1C for ClGO, SGO, and NGO, respectively. Electrochemical tests demonstrate that ClGO, SGO, and NGO electrodes deliver reversible capacities of ∼78, 199, and 240 mAh g−1 after 500 cycles at 2C (200 mA g−1). After 100 cycles at 5C (1000 mA g−1), they retain ∼90, 96, and 78 mAh g−1, showing high stability. At 10C, reversible capacities of ∼125, 210, and 260 mAh g−1 are sustained after 50 cycles. All DGO samples exhibit a mixed charge storage mechanism, primarily governed by capacitive control, with a minor contribution from diffusion-controlled processes, signifying rapid charge transfer and effective ion storage characteristics. These results highlight a simple chronoamperometric route to produce DGO anodes with excellent stability and capacity, providing a promising pathway for large-scale SIBs applications.
随着石墨烯衍生物作为新型负极材料的出现，钠离子电池（SIBs）是一种很有前途的储能器件。计时安培法能够精确、温和地合成高质量的氧化石墨烯。在这里，氯、硫和氮掺杂的石墨烯氧化物（ClGO、SGO、NGO）通过一种简单、直接、经济、环境条件的方法制备，不需要惰性气氛计时电流法，并在醚基电解质中作为SIB阳极进行测试。双lyme作为电解质溶剂的使用提高了DGO阳极的总体容量和循环寿命，因为双lyme被认为是一种有助于Na+存储的共插层电解质。形貌分析表明，所有粉末均呈二维结构，掺杂原子均匀分散。ClGO、SGO和NGO的单DGO电极在0.1C下的初始放电容量分别为~ 415、733和952 mAh g−1。电化学测试表明，在2C （200 mA g - 1）下循环500次后，ClGO、SGO和NGO电极的可逆容量分别为~ 78、199和240 mAh g - 1。在5C （1000 mA g - 1）下循环100次后，它们保持约90、96和78 mAh g - 1，表现出很高的稳定性。在10C下，50次循环后，可逆容量为~ 125、210和260 mAh g−1。所有DGO样品都表现出混合电荷存储机制，主要受电容控制，扩散控制过程的贡献较小，表明快速电荷转移和有效的离子存储特性。这些结果强调了一种简单的计时电流法生产具有优异稳定性和容量的DGO阳极的方法，为大规模sib应用提供了一条有前途的途径。
{"title":"Unveiling the effects of heteroatom (Cl, S, N) doping on chronoamperometrically synthesized graphene oxides and their interaction with glyme-based electrolytes in sodium-ion batteries","authors":"MohammedMustafa Almarzoge , Metin Gencten , Gamzenur Özsin","doi":"10.1016/j.flatc.2026.100998","DOIUrl":"10.1016/j.flatc.2026.100998","url":null,"abstract":"<div><div>Na-ion batteries (SIBs) are promising energy storage devices, with graphene derivatives emerging as new anode materials. Chronoamperometry enables precise, mild synthesis of high-quality graphene oxide. Here, chlorine-, sulfur-, and nitrogen-doped graphene oxides (ClGO, SGO, NGO) are fabricated via a simple, straightforward, cost-effective, and ambient-condition method that does not require an inert atmosphere chronoamperometric method and tested as SIB anodes in an ether-based electrolyte. The utilization of diglyme as an electrolyte solvent improved the overall capacity and cycle life of DGO anodes, as diglyme is considered a co-intercalating electrolyte that contributes to the storage of Na<sup>+</sup>. Morphological analyses reveal that all powders exhibit a two-dimensional structure with uniformly dispersed dopant atoms. The single DGO electrodes show initial discharge capacities of ∼415, 733, and 952 mAh g<sup>−1</sup> at 0.1C for ClGO, SGO, and NGO, respectively. Electrochemical tests demonstrate that ClGO, SGO, and NGO electrodes deliver reversible capacities of ∼78, 199, and 240 mAh g<sup>−1</sup> after 500 cycles at 2C (200 mA g<sup>−1</sup>). After 100 cycles at 5C (1000 mA g<sup>−1</sup>), they retain ∼90, 96, and 78 mAh g<sup>−1</sup>, showing high stability. At 10C, reversible capacities of ∼125, 210, and 260 mAh g<sup>−1</sup> are sustained after 50 cycles. All DGO samples exhibit a mixed charge storage mechanism, primarily governed by capacitive control, with a minor contribution from diffusion-controlled processes, signifying rapid charge transfer and effective ion storage characteristics. These results highlight a simple chronoamperometric route to produce DGO anodes with excellent stability and capacity, providing a promising pathway for large-scale SIBs applications.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 100998"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-22DOI: 10.1016/j.flatc.2026.101016
Anıl Doğan , Elif Akhüseyin Yıldız , Huseyin Unver , Bahadir Boyacioglu , Mustafa Yıldız , Ayhan Elmali , Ahmet Karatay
Polyethyleneimine (PEI)-functionalized nitrogen (N)-doped graphene quantum dots (PEI N-GQDs), their Schiff base-modified imine derivatives (Schiff-PEI N-GQDs), and related metal nanoparticle (Ag, Mn, Co) nanocomposites were synthesized to investigate their broadband nonlinear optical (NLO) and optical limiting (OL) properties. Imine functionalization and metal integration significantly modulate the excited-state dynamics and charge transfer properties of GQDs. While CoNPs/PEI N-GQDs and MnNPs/PEI N-GQDs systems exhibit photoluminescence profiles similar to those of pure PEI N-GQDs, AgNPs bound to 4,6-dimethoxysalicylaldehyde-modified PEI N-GQDs exhibit pronounced fluorescence quenching due to strong intramolecular charge transfer (ICT). This mechanism has been confirmed by ultrafast transient absorption spectroscopy. The analysis of femto- and pico-second Z-scan measurements has revealed a range of distinct nonlinear absorption (NA) mechanisms, with the variation in these mechanisms occurring in accordance with the wavelength, extending from the ultraviolet to the near-infrared region (400–1200 nm). AgNPs/4,6-DIMETSAL-PEI N-GQDs exhibit superior NA behavior attributed to plasmonic field enhancement and the lowest OL thresholds at 400 nm; MnNPs/PEI N-GQDs exhibit dominant NA in the near-infrared region due to defect-state-supported multi-photon absorption processes. Density functional theory (DFT) calculations reveal increased polarizability, high dipole moment, and electronic stability in the AgNP-based Schiff base system, supporting the experimentally observed strong NA behavior. These results provide a clear structure-property-mechanism relationship for the design of GQD-based nanocomposites with wavelength-selective OL performance.
{"title":"Imine-modified nitrogen-doped graphene quantum dots and metal nanocomposites: Synthesis, characterization, DFT studies, plasmon-assisted nonlinear absorption, and broadband optical limiting properties","authors":"Anıl Doğan , Elif Akhüseyin Yıldız , Huseyin Unver , Bahadir Boyacioglu , Mustafa Yıldız , Ayhan Elmali , Ahmet Karatay","doi":"10.1016/j.flatc.2026.101016","DOIUrl":"10.1016/j.flatc.2026.101016","url":null,"abstract":"<div><div>Polyethyleneimine (PEI)-functionalized nitrogen (N)-doped graphene quantum dots (PEI N-GQDs), their Schiff base-modified imine derivatives (Schiff-PEI N-GQDs), and related metal nanoparticle (Ag, Mn, Co) nanocomposites were synthesized to investigate their broadband nonlinear optical (NLO) and optical limiting (OL) properties. Imine functionalization and metal integration significantly modulate the excited-state dynamics and charge transfer properties of GQDs. While CoNPs/PEI N-GQDs and MnNPs/PEI N-GQDs systems exhibit photoluminescence profiles similar to those of pure PEI N-GQDs, AgNPs bound to 4,6-dimethoxysalicylaldehyde-modified PEI N-GQDs exhibit pronounced fluorescence quenching due to strong intramolecular charge transfer (ICT). This mechanism has been confirmed by ultrafast transient absorption spectroscopy. The analysis of femto- and pico-second <em>Z</em>-scan measurements has revealed a range of distinct nonlinear absorption (NA) mechanisms, with the variation in these mechanisms occurring in accordance with the wavelength, extending from the ultraviolet to the near-infrared region (400–1200 nm). AgNPs/4,6-DIMETSAL-PEI N-GQDs exhibit superior NA behavior attributed to plasmonic field enhancement and the lowest OL thresholds at 400 nm; MnNPs/PEI N-GQDs exhibit dominant NA in the near-infrared region due to defect-state-supported multi-photon absorption processes. Density functional theory (DFT) calculations reveal increased polarizability, high dipole moment, and electronic stability in the AgNP-based Schiff base system, supporting the experimentally observed strong NA behavior. These results provide a clear structure-property-mechanism relationship for the design of GQD-based nanocomposites with wavelength-selective OL performance.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101016"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-31DOI: 10.1016/j.flatc.2026.101008
Fatih Ciftci , Mika Sillanpää
The development of printable bioinks that simultaneously possess superior rheological fidelity and multi-functional bioactivity remains a critical challenge in extrusion-based 3D bioprinting for tissue engineering. Herein, we engineered a novel nanocomposite hydrogel scaffold comprising a structural Cellulose Nanofiber (CNF) backbone and a bioactive Fucoidan (FUC) matrix, reinforced with hydrothermally synthesized Nitrogen and Sulfur co-doped Graphene Quantum Dots (N,S-GQDs). Comprehensive physicochemical characterization confirmed the successful integration of ultrasmall (∼9.28 nm), crystalline N,S-GQDs into the polymer network. Rheological analysis revealed that the incorporation of GQDs significantly modulated the viscoelastic properties; all formulations exhibited characteristic non-Newtonian pseudoplastic (shear-thinning) behavior beneficial for extrusion, while the storage modulus (G') consistently dominated the loss modulus (G") across the frequency range, indicating the formation of a stable, solid-like gel structure with enhanced shape fidelity post-printing. Beyond mechanical reinforcement, the nanocomposites demonstrated exceptional biological functionality. The optimized scaffolds exhibited potent, dose-dependent antibacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, alongside a significant anti-inflammatory efficacy characterized by a 78.4% inhibition of protein denaturation. In vitro biological assessments revealed a transition from passive biocompatibility to active regeneration; the scaffolds induced a remarkable proliferative response in L929 fibroblasts, with cell viability exceeding 140% over 14 days. Furthermore, in a proliferation-independent scratch assay, the GQD-functionalized hydrogels significantly accelerated fibroblast migration, achieving near-complete wound closure (99.8%) within 48 h compared to 55.3% in the control group. These findings collectively establish the 3D printed CNF/FUC/N,S-GQD hydrogels as a robust, rheologically tunable, and bioactive “all-in-one” platform for advanced wound healing strategies.
{"title":"Bioactive 3D bioprinted N,S-graphene quantum dot reinforced Nanocellulose/Fucoidan scaffolds for wound healing","authors":"Fatih Ciftci , Mika Sillanpää","doi":"10.1016/j.flatc.2026.101008","DOIUrl":"10.1016/j.flatc.2026.101008","url":null,"abstract":"<div><div>The development of printable bioinks that simultaneously possess superior rheological fidelity and multi-functional bioactivity remains a critical challenge in extrusion-based 3D bioprinting for tissue engineering. Herein, we engineered a novel nanocomposite hydrogel scaffold comprising a structural Cellulose Nanofiber (CNF) backbone and a bioactive Fucoidan (FUC) matrix, reinforced with hydrothermally synthesized Nitrogen and Sulfur co-doped Graphene Quantum Dots (N,S-GQDs). Comprehensive physicochemical characterization confirmed the successful integration of ultrasmall (∼9.28 nm), crystalline N,S-GQDs into the polymer network. Rheological analysis revealed that the incorporation of GQDs significantly modulated the viscoelastic properties; all formulations exhibited characteristic non-Newtonian pseudoplastic (shear-thinning) behavior beneficial for extrusion, while the storage modulus (<em>G'</em>) consistently dominated the loss modulus (<em>G\"</em>) across the frequency range, indicating the formation of a stable, solid-like gel structure with enhanced shape fidelity post-printing. Beyond mechanical reinforcement, the nanocomposites demonstrated exceptional biological functionality. The optimized scaffolds exhibited potent, dose-dependent antibacterial activity against <em>Staphylococcus aureus</em>, <em>Escherichia coli</em>, and <em>Pseudomonas aeruginosa</em>, alongside a significant anti-inflammatory efficacy characterized by a 78.4% inhibition of protein denaturation. In vitro biological assessments revealed a transition from passive biocompatibility to active regeneration; the scaffolds induced a remarkable proliferative response in L929 fibroblasts, with cell viability exceeding 140% over 14 days. Furthermore, in a proliferation-independent scratch assay, the GQD-functionalized hydrogels significantly accelerated fibroblast migration, achieving near-complete wound closure (99.8%) within 48 h compared to 55.3% in the control group. These findings collectively establish the 3D printed CNF/FUC/N,S-GQD hydrogels as a robust, rheologically tunable, and bioactive “all-in-one” platform for advanced wound healing strategies.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101008"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-18DOI: 10.1016/j.flatc.2026.101013
Abdullah, Imran Khan, Timothy M. Ashani, Jisang Hong
Altermagnets, characterized by compensated magnetic order and spin-split electronic states even without spin–orbit coupling, have emerged as promising candidates for generating highly spin-polarized currents. Here, we investigate the spin-dependent thermoelectric properties of the Janus Cr2SeO monolayer. The system is dynamically and thermodynamically stable, exhibiting an antiferromagnetic ground state with a Néel temperature of 425 K. The spin-polarized band structure reveals a direct band gap of 1.02 eV and a significant altermagnetic spin splitting of 0.65 eV, enabling strong spin-dependent transport. The electrical conductivity (27.51 × 104 Ω−1 m−1) and electronic thermal conductivity (2.1 Wm−1 K−1) at 300 K confirm the strong spin-directional transport asymmetry. Moreover, the material exhibits an ultralow lattice thermal conductivity of 0.042 Wm−1 K−1 and large spin-dependent directional Seebeck coefficients of 2.2 mV/K (spin) and 1.8 mV/K (charge), yielding a spin-dependent directional ZT value of 0.72. These results identify Cr₂SeO as a promising altermagnetic semiconductor for efficient spin-caloritronic and thermoelectric applications.
{"title":"Directional spin seebeck effect and high-temperature spin caloritronic performance in Janus altermagnet Cr₂SeO monolayer","authors":"Abdullah, Imran Khan, Timothy M. Ashani, Jisang Hong","doi":"10.1016/j.flatc.2026.101013","DOIUrl":"10.1016/j.flatc.2026.101013","url":null,"abstract":"<div><div>Altermagnets, characterized by compensated magnetic order and spin-split electronic states even without spin–orbit coupling, have emerged as promising candidates for generating highly spin-polarized currents. Here, we investigate the spin-dependent thermoelectric properties of the Janus Cr<sub>2</sub>SeO monolayer. The system is dynamically and thermodynamically stable, exhibiting an antiferromagnetic ground state with a Néel temperature of 425 K. The spin-polarized band structure reveals a direct band gap of 1.02 eV and a significant altermagnetic spin splitting of 0.65 eV, enabling strong spin-dependent transport. The electrical conductivity (27.51 × 10<sup>4</sup> Ω<sup>−1</sup> m<sup>−1</sup>) and electronic thermal conductivity (2.1 Wm<sup>−1</sup> K<sup>−1</sup>) at 300 K confirm the strong spin-directional transport asymmetry. Moreover, the material exhibits an ultralow lattice thermal conductivity of 0.042 Wm<sup>−1</sup> K<sup>−1</sup> and large spin-dependent directional Seebeck coefficients of 2.2 mV/K (spin) and 1.8 mV/K (charge), yielding a spin-dependent directional ZT value of 0.72. These results identify Cr₂SeO as a promising altermagnetic semiconductor for efficient spin-caloritronic and thermoelectric applications.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101013"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-30DOI: 10.1016/j.flatc.2026.101006
Grandprix T.M. Kadja , Early Z. Alharissa , K. Khoiruddin , Nicholaus Prasetya , Wei-Song Hung , I.G. Wenten
The emergence of nano and sub-nanochannels in membrane applications has gained a lot of attention due to these unique dimensions and promising functional properties. The nano and sub-nanochannels applied in various two-dimensional materials (2D materials) have been discussed in this recount as well as their main characters in membrane separation for CO2 capture. Furthermore, the fundamental concept of nano- and sub-nanochannels was also elaborated in relation to the 2D materials. It would be an important aspect for executing the CO2 gas separation, which also explains its mechanism comprehensively. Not only considering material properties, but also the future outlook in computational and simulation modelling on the nano and sub-nanochannels 2D materials-based membranes are also investigated, as giving bridging tools to enhance the degree of effective and efficient materials discovery. In addition, this review would provide a clear view of engineering techniques on nano and sub-nanochannels in various 2D materials, including graphene oxide (GO), covalent organic frameworks (COFs), metal organic frameworks (MOFs), zeolites, transition metal dichalcogenides (TMDs), and MXenes, together with their actual application as CO2 separation membranes. Finally, the prospects, challenges, and upcoming direction of nano and sub-nanochannels in membrane application for CO2 capture have also evolved to gain more extensive ideas and employ mature technology and broaden the real application of nano and sub-nanochannels in various 2D materials as an effective CO2 capture.
{"title":"Engineering nano and sub-nanochannels in two dimensional membranes for enhanced CO2 capture: progress, challenges, and prospects","authors":"Grandprix T.M. Kadja , Early Z. Alharissa , K. Khoiruddin , Nicholaus Prasetya , Wei-Song Hung , I.G. Wenten","doi":"10.1016/j.flatc.2026.101006","DOIUrl":"10.1016/j.flatc.2026.101006","url":null,"abstract":"<div><div>The emergence of nano and sub-nanochannels in membrane applications has gained a lot of attention due to these unique dimensions and promising functional properties. The nano and sub-nanochannels applied in various two-dimensional materials (2D materials) have been discussed in this recount as well as their main characters in membrane separation for CO<sub>2</sub> capture. Furthermore, the fundamental concept of nano- and sub-nanochannels was also elaborated in relation to the 2D materials. It would be an important aspect for executing the CO<sub>2</sub> gas separation, which also explains its mechanism comprehensively. Not only considering material properties, but also the future outlook in computational and simulation modelling on the nano and sub-nanochannels 2D materials-based membranes are also investigated, as giving bridging tools to enhance the degree of effective and efficient materials discovery. In addition, this review would provide a clear view of engineering techniques on nano and sub-nanochannels in various 2D materials, including graphene oxide (GO), covalent organic frameworks (COFs), metal organic frameworks (MOFs), zeolites, transition metal dichalcogenides (TMDs), and MXenes, together with their actual application as CO<sub>2</sub> separation membranes. Finally, the prospects, challenges, and upcoming direction of nano and sub-nanochannels in membrane application for CO<sub>2</sub> capture have also evolved to gain more extensive ideas and employ mature technology and broaden the real application of nano and sub-nanochannels in various 2D materials as an effective CO<sub>2</sub> capture.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101006"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oral cancer is a chief global health concern due to delayed diagnosis and a lack of accessible screening tools. CYFRA 21-1, a fragment of cytokeratin-19, is a clinically established OSCC biomarker, and its salivary detection enables non-invasive early diagnosis and monitoring. Hence, this work reports the fabrication of an innovative electrochemical immunosensor based nanocomposite hydrogel comprising reduced graphene oxide (rGO), and titanium carbide MXene (Ti₃C₂), employing an eco-friendly and greener L-Cysteine (L-Cys) as a functionalizing as well as cross-linking agent. The hydrogels were synthesized in three varying ratios using GO: Ti₃C₂: L-Cysteine as precursor such as 1:1:1, 1:1:5, and 5:5:1 and characterized using XRD, FTIR, SEM, TEM, UV–Vis, XPS, BET and electrochemical techniques. Out of the three ratios, the 5:5:1 composition showed optimal electrochemical and morphological properties and was integrated onto a carbon screen-printed electrode cSPE to develop L-Cys_rGO_MXene_hydrogel/cSPE. The anti-CYFRA 21-1 antibodies were immobilized on the biosensor utiling EDC-NHS chemistry and further blocked with BSA. Electrochemical analysis using DPV demonstrated ultrasensitive [57 μA [log10(ng/mL)]−1 cm−2] CYFRA 21-1 detection with a 0.005 ng/mL detection limit, and a linear detection range from 0.098to 100 ng/mL. The biosensor showed high specificity, reproducibility, and minimal interference from salivary biomolecules. Validation with spiked artificial saliva using standard addition technique confirmed diagnostic performance showing acceptable %RSD from 0.12%–4.55%. This work, therefore, establishes a portable, biocompatible, and scalable immunosensor for non-invasive, point-of-care (POC) OSCC diagnostics, especially in resource-limited settings.
{"title":"Green Engineering of Reduced Graphene Oxide-MXene Nanocomposite Hydrogel for Sustainable and Ultrasensitive Electrochemical Immunodetection of CYFRA21-1","authors":"Shivam Saini , Damini Verma , Gopinath Packirisamy","doi":"10.1016/j.flatc.2026.101009","DOIUrl":"10.1016/j.flatc.2026.101009","url":null,"abstract":"<div><div>Oral cancer is a chief global health concern due to delayed diagnosis and a lack of accessible screening tools. CYFRA 21-1, a fragment of cytokeratin-19, is a clinically established OSCC biomarker, and its salivary detection enables non-invasive early diagnosis and monitoring. Hence, this work reports the fabrication of an innovative electrochemical immunosensor based nanocomposite hydrogel comprising reduced graphene oxide (rGO), and titanium carbide MXene (Ti₃C₂), employing an eco-friendly and greener L-Cysteine (L-Cys) as a functionalizing as well as cross-linking agent. The hydrogels were synthesized in three varying ratios using GO: Ti₃C₂: L-Cysteine as precursor such as 1:1:1, 1:1:5, and 5:5:1 and characterized using XRD, FTIR, SEM, TEM, UV–Vis, XPS, BET and electrochemical techniques. Out of the three ratios, the 5:5:1 composition showed optimal electrochemical and morphological properties and was integrated onto a carbon screen-printed electrode cSPE to develop L-Cys_rGO_MXene_hydrogel/cSPE. The anti-CYFRA 21-1 antibodies were immobilized on the biosensor utiling EDC-NHS chemistry and further blocked with BSA. Electrochemical analysis using DPV demonstrated ultrasensitive [57 μA [log<sub>10</sub>(ng/mL)]<sup>−1</sup> cm<sup>−2</sup>] CYFRA 21-1 detection with a 0.005 ng/mL detection limit, and a linear detection range from 0.098to 100 ng/mL. The biosensor showed high specificity, reproducibility, and minimal interference from salivary biomolecules. Validation with spiked artificial saliva using standard addition technique confirmed diagnostic performance showing acceptable %RSD from 0.12%–4.55%. This work, therefore, establishes a portable, biocompatible, and scalable immunosensor for non-invasive, point-of-care (POC) OSCC diagnostics, especially in resource-limited settings.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"56 ","pages":"Article 101009"},"PeriodicalIF":6.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147399568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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