The construction of a potential heterojunction catalyst with proper interface alignment has become a hot topic in the scientific community to effectively utilize solar energy. In this work, a one-dimensional TiO2 nanofiber/BiOBr S-scheme heterojunction was synthesized, and charge carrier dynamics within the interface channel were explored. In addition, we incorporated mixed phase TiO2 with point defects and oxygen vacancies, which greatly promoted the initial band edge shift from the UV region. Upon the addition of BiOBr, absorption in the visible light region of the electromagnetic (EM) spectrum was observed with a decrease in the optical band gap value. The optimized BiOBr heterojunction (BTNF1.5) revealed a higher photocatalytic RhB dye degradation efficiency due to the efficient generation and separation of charge carriers upon light irradiation. The optimum sample BTNF1.5 showed a high degradation efficiency of 98.4% with a rate constant of 47.1 min−1 at 8 min of visible light irradiation, which is double than that of the pure TiO2. Electrochemical analysis, time-resolved photoluminescence and Kelvin probe measurement revealed an S-scheme charge-transfer mechanism within the BiOBr/TiO2 system. This work provides a strategy for the facile synthesis of heterojunction photocatalysts exhibiting exceptional catalytic performance.
{"title":"Unveiling efficient S-scheme charge carrier transfer in hierarchical BiOBr/TiO2 heterojunction photocatalysts","authors":"Pooja P. Sarngan, Sheethal Sasi, Prateekshita Mukherjee, Koushik Mitra, Yuvaraj Sivalingam, Anita Swami, Uttam Kumar Ghorai, Debabrata Sarkar","doi":"10.1039/d4nr02640c","DOIUrl":"https://doi.org/10.1039/d4nr02640c","url":null,"abstract":"The construction of a potential heterojunction catalyst with proper interface alignment has become a hot topic in the scientific community to effectively utilize solar energy. In this work, a one-dimensional TiO<small><sub>2</sub></small> nanofiber/BiOBr S-scheme heterojunction was synthesized, and charge carrier dynamics within the interface channel were explored. In addition, we incorporated mixed phase TiO<small><sub>2</sub></small> with point defects and oxygen vacancies, which greatly promoted the initial band edge shift from the UV region. Upon the addition of BiOBr, absorption in the visible light region of the electromagnetic (EM) spectrum was observed with a decrease in the optical band gap value. The optimized BiOBr heterojunction (BTNF<small><sub>1.5</sub></small>) revealed a higher photocatalytic RhB dye degradation efficiency due to the efficient generation and separation of charge carriers upon light irradiation. The optimum sample BTNF<small><sub>1.5</sub></small> showed a high degradation efficiency of 98.4% with a rate constant of 47.1 min<small><sup>−1</sup></small> at 8 min of visible light irradiation, which is double than that of the pure TiO<small><sub>2</sub></small>. Electrochemical analysis, time-resolved photoluminescence and Kelvin probe measurement revealed an S-scheme charge-transfer mechanism within the BiOBr/TiO<small><sub>2</sub></small> system. This work provides a strategy for the facile synthesis of heterojunction photocatalysts exhibiting exceptional catalytic performance.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142276128","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}
Owing to their unique optical properties and atomically precise structures, metal nanoclusters (MNCs) constitute a new generation of optical probe materials. This mini-review provides a brief overview of luminescence mechanisms and modulation methods of luminescent metal nanoclusters in recent years. Based on these photophysical phenomena, the applications of cluster-based optical probes in optical bioimaging and related sensing, disease diagnosis, and treatment are summarized. Some challenges were also listed in the end.
{"title":"Luminescent Metal Nanoclusters and Their Application in Bioimaging","authors":"Wenwen Fei, Sheng-Yan Tang, Man-Bo Li","doi":"10.1039/d4nr03111c","DOIUrl":"https://doi.org/10.1039/d4nr03111c","url":null,"abstract":"Owing to their unique optical properties and atomically precise structures, metal nanoclusters (MNCs) constitute a new generation of optical probe materials. This mini-review provides a brief overview of luminescence mechanisms and modulation methods of luminescent metal nanoclusters in recent years. Based on these photophysical phenomena, the applications of cluster-based optical probes in optical bioimaging and related sensing, disease diagnosis, and treatment are summarized. Some challenges were also listed in the end.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245879","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}
Tieu Ngoc Nguyen, Imène Chebbi, Raphaël Le Fèvre, François Guyot, Edouard Alphandéry
We report a method to prepare biocompatible, stable, and highly pure iron oxide nano-minerals by following the steps consisting of: (i) amplifying magnetotactic bacteria in non-toxic minimal growth media; (ii) extracting magnetosomes from magnetotactic bacteria under alkaline lysis; (iii) heating magnetosomes above 400 °C to yield sterile magnetosome minerals, M-uncoated, devoid of active non-denatured bacterial organic material; (iv) coating M-uncoated with biocompatible carboxymethyl-dextran (CMD) compounds to yield stable M-CMD; (v) adding 5% sorbitol to M-CMD; and (vi) lyophilizing these mixtures, resulting in formulated nano-minerals in powder forms, designated as (M-CMD)F. The long-term stability of the final products is demonstrated by re-suspending (M-CMD)F in water after 12 months of storage, and by showing that these formulated magnetosomes have preserved their stability in suspension, chain arrangement, carbon content, surface charge, and surface composition. Furthermore, the formulation is optimized to yield an isotonic magnetosome suspension with an osmolality of between 275 and 290 mOsm kg−1 H2O upon reconstitution. On one hand, these formulated magnetosomes are fully biocompatible, i.e. sterile, non-pyrogenic, and non-cytotoxic towards 3T3, L929, and V79 healthy cells up to 1 mg mL−1 NP concentration iron. On the other hand, when they are brought into the presence of PC3-Luc prostate tumor cells and heated moderately at ∼41–46 °C for 20–30 minutes under low-intensity ultrasound or alternating magnetic field conditions, they efficiently destroy these tumor cells.
{"title":"Stable pharmaceutical composition of cryo-protected non-pyrogenic isotonic chains of magnetosomes for efficient tumor cell destruction at 45 ± 1 °C under alternating magnetic field or ultrasound application","authors":"Tieu Ngoc Nguyen, Imène Chebbi, Raphaël Le Fèvre, François Guyot, Edouard Alphandéry","doi":"10.1039/d4nr02284j","DOIUrl":"https://doi.org/10.1039/d4nr02284j","url":null,"abstract":"We report a method to prepare biocompatible, stable, and highly pure iron oxide nano-minerals by following the steps consisting of: (i) amplifying magnetotactic bacteria in non-toxic minimal growth media; (ii) extracting magnetosomes from magnetotactic bacteria under alkaline lysis; (iii) heating magnetosomes above 400 °C to yield sterile magnetosome minerals, M-uncoated, devoid of active non-denatured bacterial organic material; (iv) coating M-uncoated with biocompatible carboxymethyl-dextran (CMD) compounds to yield stable M-CMD; (v) adding 5% sorbitol to M-CMD; and (vi) lyophilizing these mixtures, resulting in formulated nano-minerals in powder forms, designated as (M-CMD)<small><sub>F</sub></small>. The long-term stability of the final products is demonstrated by re-suspending (M-CMD)<small><sub>F</sub></small> in water after 12 months of storage, and by showing that these formulated magnetosomes have preserved their stability in suspension, chain arrangement, carbon content, surface charge, and surface composition. Furthermore, the formulation is optimized to yield an isotonic magnetosome suspension with an osmolality of between 275 and 290 mOsm kg<small><sup>−1</sup></small> H<small><sub>2</sub></small>O upon reconstitution. On one hand, these formulated magnetosomes are fully biocompatible, <em>i.e.</em> sterile, non-pyrogenic, and non-cytotoxic towards 3T3, L929, and V79 healthy cells up to 1 mg mL<small><sup>−1</sup></small> NP concentration iron. On the other hand, when they are brought into the presence of PC3-Luc prostate tumor cells and heated moderately at ∼41–46 °C for 20–30 minutes under low-intensity ultrasound or alternating magnetic field conditions, they efficiently destroy these tumor cells.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245857","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}
Shulin Li, Ning Feng, Mengdi Sun, Yuxiang Sha, Xia Xin, Hui Zhao, Hongguang Li
Elucidating the mechanism of chiral transfer is key to regulating chiral expression and generalizing the structure–property relationship of chiral functional systems. However, it is still an important challenge to select novel building blocks to achieve chiral induction, chiral transfer and chiral modulation. Liquid crystals (LCs) can be considered as promising smart soft materials due to their responsiveness and adaptability. Confining chiral metal nanoclusters (NCs) in an achiral LC phase to construct chiral LCs provides an expanded strategy for the self-assembly of chiral metal NCs in different matrices. Herein, chiral glutathione-stabilized copper NCs (G-SH-Cu NCs)/polyoxyethylene tert-octylphenyl ether (TX-100) LCs were constructed and systematically investigated. The results showed that the introduction of G-SH-Cu NCs into TX-100 LCs induced the generation of supramolecular chirality. More interestingly, the circular dichroism (CD) handedness can be controlled by changing the amount of TX-100 or G-SH-Cu NCs; when the ratio of G-SH-Cu NCs and TX-100 was proportionally matched, the strength of the noncovalent interactions was sufficient to induce chiral inversion. Meanwhile, TX-100 LCs provide effective confinement of G-SH-Cu NCs, which improves the expression of asymmetry at the aggregation level and induces a 2-fold enhancement of the circularly polarized luminescence (CPL) signal. This work realizes the spatial amplification of chirality through dopants in LCs, which provides an effective method for accurately regulating the supramolecular chirality of metal NCs in the LC phase.
{"title":"Liquid crystal-mediated self-assembly of copper nanoclusters with induced circular dichroism and amplified circularly polarized luminescence","authors":"Shulin Li, Ning Feng, Mengdi Sun, Yuxiang Sha, Xia Xin, Hui Zhao, Hongguang Li","doi":"10.1039/d4nr03125c","DOIUrl":"https://doi.org/10.1039/d4nr03125c","url":null,"abstract":"Elucidating the mechanism of chiral transfer is key to regulating chiral expression and generalizing the structure–property relationship of chiral functional systems. However, it is still an important challenge to select novel building blocks to achieve chiral induction, chiral transfer and chiral modulation. Liquid crystals (LCs) can be considered as promising smart soft materials due to their responsiveness and adaptability. Confining chiral metal nanoclusters (NCs) in an achiral LC phase to construct chiral LCs provides an expanded strategy for the self-assembly of chiral metal NCs in different matrices. Herein, chiral glutathione-stabilized copper NCs (G-SH-Cu NCs)/polyoxyethylene <em>tert</em>-octylphenyl ether (TX-100) LCs were constructed and systematically investigated. The results showed that the introduction of G-SH-Cu NCs into TX-100 LCs induced the generation of supramolecular chirality. More interestingly, the circular dichroism (CD) handedness can be controlled by changing the amount of TX-100 or G-SH-Cu NCs; when the ratio of G-SH-Cu NCs and TX-100 was proportionally matched, the strength of the noncovalent interactions was sufficient to induce chiral inversion. Meanwhile, TX-100 LCs provide effective confinement of G-SH-Cu NCs, which improves the expression of asymmetry at the aggregation level and induces a 2-fold enhancement of the circularly polarized luminescence (CPL) signal. This work realizes the spatial amplification of chirality through dopants in LCs, which provides an effective method for accurately regulating the supramolecular chirality of metal NCs in the LC phase.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245905","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}
Magnetic/dielectric composites can achieve high-efficiency electromagnetic wave (EMW) absorption performance by integrating multiple mechanisms such as dielectric loss and magnetic loss. The bimetallic metal–organic frameworks (MOFs) assembled from ferrocene (Fc) derivative-based bridging ligands are considered ideal precursors for the preparation of magnetic/dielectric composites due to tailored alloy components with magnetic losses. Herein, a novel CoFe/C composite with nanoflower structures is successfully obtained via an in situ growth strategy to decompose an Fc-based bimetallic MOF assembled from 1,1′-ferrocene dicarboxylic acid as bridging ligands and Co2+ ions. Notably, the nanoflower structures of the obtained composites provide an effective path for the scattering and reflection of the EMW, thereby improving the impedance matching by combining dielectric and magnetic loss. The CoFe/C composite exhibits excellent EMW absorption performance and has a minimum reflection loss of −61.6 dB at 3.7 mm and an effective absorption bandwidth of 6.24 GHz at a corresponding thickness of 2.2 mm. Moreover, the obtained composite exhibits lightweight characteristics and a low radar cross-section. This work presents a novel method through Fc-based bimetallic MOF derivatives to design and develop novel magnetic/dielectric composites with efficient EMW absorption properties for comprehensive applications.
{"title":"Fabrication of flower-like CoFe/C composites derived from ferrocene-based metal–organic frameworks: an in situ growth strategy toward high-efficiency electromagnetic wave absorption","authors":"Xueling Wang, Xuan Zhang, Jiaqi Lu, Zhiliang Liu","doi":"10.1039/d4nr02661f","DOIUrl":"https://doi.org/10.1039/d4nr02661f","url":null,"abstract":"Magnetic/dielectric composites can achieve high-efficiency electromagnetic wave (EMW) absorption performance by integrating multiple mechanisms such as dielectric loss and magnetic loss. The bimetallic metal–organic frameworks (MOFs) assembled from ferrocene (Fc) derivative-based bridging ligands are considered ideal precursors for the preparation of magnetic/dielectric composites due to tailored alloy components with magnetic losses. Herein, a novel CoFe/C composite with nanoflower structures is successfully obtained <em>via</em> an <em>in situ</em> growth strategy to decompose an Fc-based bimetallic MOF assembled from 1,1′-ferrocene dicarboxylic acid as bridging ligands and Co<small><sup>2+</sup></small> ions. Notably, the nanoflower structures of the obtained composites provide an effective path for the scattering and reflection of the EMW, thereby improving the impedance matching by combining dielectric and magnetic loss. The CoFe/C composite exhibits excellent EMW absorption performance and has a minimum reflection loss of −61.6 dB at 3.7 mm and an effective absorption bandwidth of 6.24 GHz at a corresponding thickness of 2.2 mm. Moreover, the obtained composite exhibits lightweight characteristics and a low radar cross-section. This work presents a novel method through Fc-based bimetallic MOF derivatives to design and develop novel magnetic/dielectric composites with efficient EMW absorption properties for comprehensive applications.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236193","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}
Non-toxic nanoscale materials are widely employed for different healthcare applications but their performance is still considerably limited. In this paper, various approaches of the environment-friendly ultrafast laser processing were employed for remodelling IV group semiconductor nanostructures and synthesizing highly-stable (ξ-potential is up to –47 mV) colloidal solutions of plasmonic (525 nm) nanocomposites with a strong size-dependent chemical content. All nanocomposites exhibited a remarkable lamp-excited multi-band blue emission centred at around 420 nm that is considerably (~10-fold for Au-SiC) stronger for nanocomposites prepared by the laser co-fragmentation technique. The latter formed a larger amount of smaller narrowly-dispersed (~ 4 nm for Au-Si) plasmonic nanostructures as compared to the direct laser ablation. Moreover, it also led to a higher content of semiconductor elements (~1.7-fold for Au-Ge) in nanocomposites correlating with a lower (~ 30 %) electrical conductivity. Aqueous colloidal solutions revealed a higher degree (~ 80 %) of the femtosecond laser-induced heating for all nanocomposites formed by the direct laser ablation. These findings highlight the peculiarities of the used laser processing approaches and considerably facilitate designing of specific multi-modal plasmono-fluorescence (biosensing, bioimaging, hyperthermia) nanocomposites with a required performance significantly enlarging the application area of semiconductor nanostructures.
{"title":"Design of “Green” Plasmonic Nanocomposites with Multi-Band Blue Emission for Ultrafast Laser Hyperthermia","authors":"Yury Ryabchikov","doi":"10.1039/d4nr03120b","DOIUrl":"https://doi.org/10.1039/d4nr03120b","url":null,"abstract":"Non-toxic nanoscale materials are widely employed for different healthcare applications but their performance is still considerably limited. In this paper, various approaches of the environment-friendly ultrafast laser processing were employed for remodelling IV group semiconductor nanostructures and synthesizing highly-stable (ξ-potential is up to –47 mV) colloidal solutions of plasmonic (525 nm) nanocomposites with a strong size-dependent chemical content. All nanocomposites exhibited a remarkable lamp-excited multi-band blue emission centred at around 420 nm that is considerably (~10-fold for Au-SiC) stronger for nanocomposites prepared by the laser co-fragmentation technique. The latter formed a larger amount of smaller narrowly-dispersed (~ 4 nm for Au-Si) plasmonic nanostructures as compared to the direct laser ablation. Moreover, it also led to a higher content of semiconductor elements (~1.7-fold for Au-Ge) in nanocomposites correlating with a lower (~ 30 %) electrical conductivity. Aqueous colloidal solutions revealed a higher degree (~ 80 %) of the femtosecond laser-induced heating for all nanocomposites formed by the direct laser ablation. These findings highlight the peculiarities of the used laser processing approaches and considerably facilitate designing of specific multi-modal plasmono-fluorescence (biosensing, bioimaging, hyperthermia) nanocomposites with a required performance significantly enlarging the application area of semiconductor nanostructures.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236195","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}
Priyanshi Agnihotri, Divya Dheer, Anvi Sangwan, Vysakh C Chandran, Nimisha A Mavlankar, Gunjan Hooda, Debabrata Patra, Asish Pal
Multifunctional colloidal microgels that exhibit stimuli-responsive behavior and excellent biocompatibility have attracted particular attention for developing functional compartmentalized networks. Herein, a series of stimuli-responsive microgels (M0, M1 and M2) were designed by copolymerization of di(ethylene glycol) methyl ether methacrylate (DEGMA) and methacrylic acid (MAA) monomers using hydroxy ethyl methacrylate-coupled azobenzene (HEMA-Az) and ethylene glycol dimetharylate (EGDMA) as crosslinkers. The behaviour of the microgels in response to temperature-, pH- and light was thoroughly investigated by using spectroscopic, microscopic and light scattering techniques. Interestingly, the microgels deswelled with increase in temperature, decrease in pH and with the irradiation of UV light. Such a reversible swelling/deswelling behaviour was exploited for mircogel M2 showing better photoactuation at pH 5 with higher fluid pumping velocity. The actuating microgel M2 was optimized for the loading of ciprofloxacin (Cf) drug to study the release at different temperature, pH and light conditions. Finally, microgel M2 exhibited photoresponsive Cf release in pH 5 and 37 oC toward application in on-demand drug release.
{"title":"Design of Multi-responsive and Actuating Microgel toward On-demand Drug Release","authors":"Priyanshi Agnihotri, Divya Dheer, Anvi Sangwan, Vysakh C Chandran, Nimisha A Mavlankar, Gunjan Hooda, Debabrata Patra, Asish Pal","doi":"10.1039/d4nr02728k","DOIUrl":"https://doi.org/10.1039/d4nr02728k","url":null,"abstract":"Multifunctional colloidal microgels that exhibit stimuli-responsive behavior and excellent biocompatibility have attracted particular attention for developing functional compartmentalized networks. Herein, a series of stimuli-responsive microgels (M0, M1 and M2) were designed by copolymerization of di(ethylene glycol) methyl ether methacrylate (DEGMA) and methacrylic acid (MAA) monomers using hydroxy ethyl methacrylate-coupled azobenzene (HEMA-Az) and ethylene glycol dimetharylate (EGDMA) as crosslinkers. The behaviour of the microgels in response to temperature-, pH- and light was thoroughly investigated by using spectroscopic, microscopic and light scattering techniques. Interestingly, the microgels deswelled with increase in temperature, decrease in pH and with the irradiation of UV light. Such a reversible swelling/deswelling behaviour was exploited for mircogel M2 showing better photoactuation at pH 5 with higher fluid pumping velocity. The actuating microgel M2 was optimized for the loading of ciprofloxacin (Cf) drug to study the release at different temperature, pH and light conditions. Finally, microgel M2 exhibited photoresponsive Cf release in pH 5 and 37 oC toward application in on-demand drug release.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236196","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}
Eduardo D. Martínez, Luiz H. A. R. Ferreira, Albano N. Carneiro Neto, Carlos D. S. Brites, Luís D. Carlos
The quest for enhancing the upconversion luminescence (UCL) efficiency of rare-earth doped materials has been a common target in nanophotonics research. Plasmonic nanoarchitectures have proven potential for amplifying UCL signals, prompting investigations into localized enhancement effects within noble metal nanostructures. In this work we investigate the localized enhancement of UCL in silver nanowire (AgNW) networks coated with upconversion nanoparticles (UCNPs) by employing hyperspectral microscopy to unveil distinctive regions of local enhancement. Our study reveals that three-photon upconversion processes predominantly occur at hot-spots in nanowire junctions, contributing to heightened luminescence intensity on AgNW networks. Intriguingly, our findings demonstrate that enhancement on AgNWs introduces significant artifacts for thermometry based on ratiometric analysis of the emission spectra, resulting in the observation of artificial thermal gradients. To address this challenge, we developed correction methods that were successfully applied to mitigate this effect, enabling the generation of accurate thermal maps and the realization of dynamic thermal measurements. We quantified the distance-dependent enhancement profiles and studied the effect of temperature by exploiting the heat dissipation under varying electrical voltages across the electrically percolated AgNW networks. The observations were confirmed through numerical calculations of the enhancement factor and the energy transfer rates. This comprehensive investigation sheds light on the complex interplay between plasmonic nanostructures, three-photon upconversion processes, and their influence on thermal sensing applications. The presented hyperspectral method not only allows a direct visualization of plasmonic hot-spots but also advances our understanding of localized enhancements. The correction methods applied to analyze the emission spectra also contribute to the refinement of accurate temperature mapping using UCNPs, thereby enhancing the reliability of this thermal sensing technology.
{"title":"Localized three-photon upconversion enhancement in silver nanowire networks and its effect in thermal sensing","authors":"Eduardo D. Martínez, Luiz H. A. R. Ferreira, Albano N. Carneiro Neto, Carlos D. S. Brites, Luís D. Carlos","doi":"10.1039/d4nr02484b","DOIUrl":"https://doi.org/10.1039/d4nr02484b","url":null,"abstract":"The quest for enhancing the upconversion luminescence (UCL) efficiency of rare-earth doped materials has been a common target in nanophotonics research. Plasmonic nanoarchitectures have proven potential for amplifying UCL signals, prompting investigations into localized enhancement effects within noble metal nanostructures. In this work we investigate the localized enhancement of UCL in silver nanowire (AgNW) networks coated with upconversion nanoparticles (UCNPs) by employing hyperspectral microscopy to unveil distinctive regions of local enhancement. Our study reveals that three-photon upconversion processes predominantly occur at hot-spots in nanowire junctions, contributing to heightened luminescence intensity on AgNW networks. Intriguingly, our findings demonstrate that enhancement on AgNWs introduces significant artifacts for thermometry based on ratiometric analysis of the emission spectra, resulting in the observation of artificial thermal gradients. To address this challenge, we developed correction methods that were successfully applied to mitigate this effect, enabling the generation of accurate thermal maps and the realization of dynamic thermal measurements. We quantified the distance-dependent enhancement profiles and studied the effect of temperature by exploiting the heat dissipation under varying electrical voltages across the electrically percolated AgNW networks. The observations were confirmed through numerical calculations of the enhancement factor and the energy transfer rates. This comprehensive investigation sheds light on the complex interplay between plasmonic nanostructures, three-photon upconversion processes, and their influence on thermal sensing applications. The presented hyperspectral method not only allows a direct visualization of plasmonic hot-spots but also advances our understanding of localized enhancements. The correction methods applied to analyze the emission spectra also contribute to the refinement of accurate temperature mapping using UCNPs, thereby enhancing the reliability of this thermal sensing technology.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236816","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}
Rui Guo, Lidan Wang, Feifan Chen, Kaiwen Li, Yue Gao, Chenqwei Shen, Xuan Ye, Senping Liu, Ya Wang, Zeshen Li, Peng Li, Zhen Xu, Yingjun Liu, Chao Gao
The integration of graphene and nonionic water-soluble polymers has generated useful composites with high performances and rich functionalities. These attractive graphene composites are usually processed from aqueous mixture of graphene oxide (GO) precursor and polymers, such as synthetic polyvinyl alcohol and natural cellulose. In this widely known preparation method, the miscibility of GO and nonionic water-soluble polymers seems as an intuitional sense, but was disputed by some observations of gelation and aggregation as mixed. Here, we re-examine the miscibility of GO and nonionic water-soluble polymers and confirm their general coaggregation caused by hydrogen bond interaction. The increasing GO concentration turns the stable miscibility by surface absorption to aggregation with transient hydrogen bond crosslinking. We propose a preheat mixing strategy to prepare homogenous solution of GO and nonionic water-soluble polymers at any arbitrary ratio. The re-exploited miscibility allows the fabrication of homogeneous composite papers with a renewal high performance trend. The hydrogen bond regulating miscibility refreshes understanding on graphene/water-soluble polymeric composites and directs an ecofriendly interaction control method to modulate assembly for structures and materials.
石墨烯与非离子水溶性聚合物的结合产生了具有高性能和丰富功能的有用复合材料。这些极具吸引力的石墨烯复合材料通常由氧化石墨烯（GO）前体和聚合物（如合成聚乙烯醇和天然纤维素）的水性混合物加工而成。在这种广为人知的制备方法中，GO 与非离子水溶性聚合物的混溶性似乎是一种直觉，但在混合过程中出现的凝胶化和聚集现象却引起了争议。在此，我们重新研究了 GO 与非离子水溶性聚合物的相溶性，并证实了它们因氢键作用而产生的普遍共聚现象。随着 GO 浓度的增加，由表面吸收引起的稳定混溶转变为瞬时氢键交联的聚集。我们提出了一种预热混合策略，以任意比例制备 GO 和非离子水溶性聚合物的均匀溶液。通过重新利用混溶性，可以制造出均匀的复合纸张，并呈现出更新的高性能趋势。氢键调节混溶性刷新了人们对石墨烯/水溶性聚合物复合材料的认识，并为调节结构和材料的组装提供了一种生态友好的相互作用控制方法。
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Andrew Selvadoss, Helna M. Baby, Hengli Zhang, Ambika Bajpayee
Exosomes are nanosized, lipid membrane vesicles secreted by cells, facilitating intercellular communication by transferring their cargo from parent to recipient cells. This capability enables biological crosstalk across multiple tissues and cells. Extensive research has been conducted on their role in the pathogenesis of degenerative musculoskeletal diseases such as osteoarthritis (OA), a chronic and painful joint disease that particularly affects cartilage. Currently, no effective treatment exists for OA. Given that exosomes naturally modulate synovial joint inflammation and facilitate cartilage matrix synthesis, they are promising candidates as next generation nanocarriers for OA therapy. Recent advancements have focused on engineering exosomes through endogenous and exogenous approaches to enhance their joint retention, cartilage and chondrocyte targeting properties, and therapeutic content enrichment, further increasing their potential for OA drug delivery. Notably, charge-reversed exosomes that utilize electrostatic binding interactions with cartilage anionic aggrecan glycosaminoglycans have demonstrated the ability to penetrate the full thickness of early-stage arthritic cartilage tissue following intra-articular administration, maximizing their therapeutic potential. These exosomes offer a non-viral, naturally derived, cell-free carrier for OA drug and gene delivery applications. Efforts to standardize exosome harvest, engineering, and property characterization methods, along with scaling up production, will facilitate more efficient and rapid clinical translation. This article reviews the current state-of-the-art, explores opportunities for exosomes as OA therapeutics, and identifies potential challenges in their clinical translation.
外泌体是细胞分泌的纳米级脂质膜囊泡，通过将货物从母细胞转移到受体细胞，促进细胞间的交流。这种能力可在多个组织和细胞间进行生物串联。人们对它们在退行性肌肉骨骼疾病（如骨关节炎）的发病机制中的作用进行了广泛的研究，骨关节炎是一种慢性疼痛性关节疾病，对软骨的影响尤为严重。目前，骨关节炎还没有有效的治疗方法。鉴于外泌体可自然调节滑膜关节炎症并促进软骨基质的合成，它们有望成为治疗 OA 的下一代纳米载体。最近的研究进展主要集中在通过内源性和外源性方法对外泌体进行工程化，以增强其关节保持力、软骨和软骨细胞靶向特性以及富集治疗成分，从而进一步提高其在 OA 药物递送方面的潜力。值得注意的是，利用静电结合与软骨阴离子凝集素氨基糖相互作用的电荷反转外泌体已证明能够在关节内给药后穿透早期关节炎软骨组织的全部厚度，最大限度地发挥其治疗潜力。这些外泌体为 OA 药物和基因递送应用提供了一种非病毒、天然衍生、无细胞的载体。努力实现外泌体收获、工程和特性表征方法的标准化，同时扩大生产规模，将促进更高效、更快速的临床转化。本文回顾了当前的先进技术，探讨了外泌体作为OA疗法的机遇，并指出了其临床转化过程中可能面临的挑战。
{"title":"Harnessing Exosomes for Advanced Osteoarthritis Therapy","authors":"Andrew Selvadoss, Helna M. Baby, Hengli Zhang, Ambika Bajpayee","doi":"10.1039/d4nr02792b","DOIUrl":"https://doi.org/10.1039/d4nr02792b","url":null,"abstract":"Exosomes are nanosized, lipid membrane vesicles secreted by cells, facilitating intercellular communication by transferring their cargo from parent to recipient cells. This capability enables biological crosstalk across multiple tissues and cells. Extensive research has been conducted on their role in the pathogenesis of degenerative musculoskeletal diseases such as osteoarthritis (OA), a chronic and painful joint disease that particularly affects cartilage. Currently, no effective treatment exists for OA. Given that exosomes naturally modulate synovial joint inflammation and facilitate cartilage matrix synthesis, they are promising candidates as next generation nanocarriers for OA therapy. Recent advancements have focused on engineering exosomes through endogenous and exogenous approaches to enhance their joint retention, cartilage and chondrocyte targeting properties, and therapeutic content enrichment, further increasing their potential for OA drug delivery. Notably, charge-reversed exosomes that utilize electrostatic binding interactions with cartilage anionic aggrecan glycosaminoglycans have demonstrated the ability to penetrate the full thickness of early-stage arthritic cartilage tissue following intra-articular administration, maximizing their therapeutic potential. These exosomes offer a non-viral, naturally derived, cell-free carrier for OA drug and gene delivery applications. Efforts to standardize exosome harvest, engineering, and property characterization methods, along with scaling up production, will facilitate more efficient and rapid clinical translation. This article reviews the current state-of-the-art, explores opportunities for exosomes as OA therapeutics, and identifies potential challenges in their clinical translation.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245914","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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