Biofluids are ideal sample sources for wearable in situ surface-enhanced Raman scattering (IS-SERS) sensors due to their noninvasive collection. However, the limited spatial reach of conventional hot spots (HSs), coupled with the fluidic and biocomplex nature of biofluids, means that only a small portion of target analytes can be effectively captured inside the HSs. To overcome this, we propose a metal@MOF particle-in-cavity (MMPIC) detection model. This architecture enhances the cascade electric field, expanding and concentrating HSs within and around the MOF dielectric. The integration of conical nanocavities with nanoporous MOFs enables effective analyte confinement and enrichment within the MOF matrix as well, ensuring colocalization with HSs in the same microregion. Additionally, the molecular sieving and graded refractive index properties of the MMPIC structure provide strong resistance to interference from both biofluids and their components. Together, these features improve both the sensitivity and robustness of the model. As a proof of concept, a microfluidic patch and a smart mask were developed based on the MMPIC model, enabling precise quantification of biomarkers-such as pH, glucose, ammonia, and 4-ethylbenzaldehyde-down to 1 ppb in real human sweat and exhaled breath. This work introduces a universal wearable IS-SERS detection model and validates its applicability across diverse real-world scenarios, offering valuable guidance for future wearable in situ sensing technologies.
{"title":"Wearable In Situ SERS Sensors Based on the Metal@MOF Particle-in-Cavity Model: Suitable for Detection of Multifarious Biomarkers in Different Biofluids of Humans.","authors":"Hao Li,Chongfeng Cao,Fengcai Lei,Minghui Du,Xiaofei Zhao,Zhen Li,Chao Zhang,Yang Jiao,Jing Yu","doi":"10.1021/acssensors.5c04143","DOIUrl":"https://doi.org/10.1021/acssensors.5c04143","url":null,"abstract":"Biofluids are ideal sample sources for wearable in situ surface-enhanced Raman scattering (IS-SERS) sensors due to their noninvasive collection. However, the limited spatial reach of conventional hot spots (HSs), coupled with the fluidic and biocomplex nature of biofluids, means that only a small portion of target analytes can be effectively captured inside the HSs. To overcome this, we propose a metal@MOF particle-in-cavity (MMPIC) detection model. This architecture enhances the cascade electric field, expanding and concentrating HSs within and around the MOF dielectric. The integration of conical nanocavities with nanoporous MOFs enables effective analyte confinement and enrichment within the MOF matrix as well, ensuring colocalization with HSs in the same microregion. Additionally, the molecular sieving and graded refractive index properties of the MMPIC structure provide strong resistance to interference from both biofluids and their components. Together, these features improve both the sensitivity and robustness of the model. As a proof of concept, a microfluidic patch and a smart mask were developed based on the MMPIC model, enabling precise quantification of biomarkers-such as pH, glucose, ammonia, and 4-ethylbenzaldehyde-down to 1 ppb in real human sweat and exhaled breath. This work introduces a universal wearable IS-SERS detection model and validates its applicability across diverse real-world scenarios, offering valuable guidance for future wearable in situ sensing technologies.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"22 1","pages":"XXX"},"PeriodicalIF":8.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146056390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-27DOI: 10.1021/acssensors.5c03258
Sihao Zhi, Liang Zhao, Yunpeng Xing, Hongda Zhang, Chengchao Yu, Teng Fei, Sen Liu, Haiyan Zhang, Tong Zhang
An increase in surface-adsorbed oxygen species presents unique opportunities to improve the sensing performance of metal oxide-based gas sensors. However, the instability of surface-adsorbed oxygen species, especially in the gas sensing process, decreases the sensing performance. This study reveals the performance‒stability paradox of surface-adsorbed oxygen species for Co3O4-based acetone sensors. A hydrothermal synthesis method assisted by P123 was used to prepare Co3O4 with an appropriate surface-adsorbed oxygen species (designated as Co3O4-AP). Unlike Co3O4 with less surface-adsorbed oxygen species, as-prepared Co3O4-AP exhibited a high response value of 19.0 (100 ppm acetone) on the first day but decreased to 13.9 on the seventh day, with a relative standard deviation of 15.7% in terms of resistance and 15.0% in terms of response values, respectively, owing to the loss of surface-adsorbed oxygen species during the sensing process (mainly the filling of oxygen vacancies by O2). Owing to the instability of surface-adsorbed oxygen species, aging at 240 °C in air for 2 days was rationally performed for Co3O4-AP, decreasing the surface-adsorbed oxygen species concentration and improving the stability of Co3O4-AP. Notably, after aging for 2 days, the Co3O4-AP sensor achieves a response value of 12.9 (100 ppm acetone), high selectivity, and good stability (relative standard deviations of 7.0 and 9.1% in terms of resistance and response values, respectively), outperforming acetone sensors based on Co3O4 obtained by hydrothermal synthesis without P123 (7.2), the coprecipitation method (7.6), and the direct calcination method (3.5). Our work provides new insights into overcoming the performance‒stability trade-off and designing highly stable and high-performing gas sensors.
{"title":"Optimizing the Stability of Co3O4 for Acetone Sensing by Oxygen Vacancy Alteration","authors":"Sihao Zhi, Liang Zhao, Yunpeng Xing, Hongda Zhang, Chengchao Yu, Teng Fei, Sen Liu, Haiyan Zhang, Tong Zhang","doi":"10.1021/acssensors.5c03258","DOIUrl":"https://doi.org/10.1021/acssensors.5c03258","url":null,"abstract":"An increase in surface-adsorbed oxygen species presents unique opportunities to improve the sensing performance of metal oxide-based gas sensors. However, the instability of surface-adsorbed oxygen species, especially in the gas sensing process, decreases the sensing performance. This study reveals the performance‒stability paradox of surface-adsorbed oxygen species for Co<sub>3</sub>O<sub>4</sub>-based acetone sensors. A hydrothermal synthesis method assisted by P123 was used to prepare Co<sub>3</sub>O<sub>4</sub> with an appropriate surface-adsorbed oxygen species (designated as Co<sub>3</sub>O<sub>4</sub>-AP). Unlike Co<sub>3</sub>O<sub>4</sub> with less surface-adsorbed oxygen species, as-prepared Co<sub>3</sub>O<sub>4</sub>-AP exhibited a high response value of 19.0 (100 ppm acetone) on the first day but decreased to 13.9 on the seventh day, with a relative standard deviation of 15.7% in terms of resistance and 15.0% in terms of response values, respectively, owing to the loss of surface-adsorbed oxygen species during the sensing process (mainly the filling of oxygen vacancies by O<sub>2</sub>). Owing to the instability of surface-adsorbed oxygen species, aging at 240 °C in air for 2 days was rationally performed for Co<sub>3</sub>O<sub>4</sub>-AP, decreasing the surface-adsorbed oxygen species concentration and improving the stability of Co<sub>3</sub>O<sub>4</sub>-AP. Notably, after aging for 2 days, the Co<sub>3</sub>O<sub>4</sub>-AP sensor achieves a response value of 12.9 (100 ppm acetone), high selectivity, and good stability (relative standard deviations of 7.0 and 9.1% in terms of resistance and response values, respectively), outperforming acetone sensors based on Co<sub>3</sub>O<sub>4</sub> obtained by hydrothermal synthesis without P123 (7.2), the coprecipitation method (7.6), and the direct calcination method (3.5). Our work provides new insights into overcoming the performance‒stability trade-off and designing highly stable and high-performing gas sensors.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"51 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Online exhaled breath analysis holds great promise for noninvasive medical diagnostics, health monitoring, and environmental exposure assessment. However, the complex nature of the breath matrix and strong interference from water vapor and carbon dioxide make high-precision, real-time sensing challenging, often requiring large and costly systems such as mass spectrometers. In this work, we present a compact differential photoacoustic gas sensor for end-tidal carbon dioxide (ETCO2) and end-tidal oxygen (ETO2) monitoring. The sensor employs a dual-resonator photoacoustic cell with resonant frequencies of 4110 and 13,115 Hz for selective ETCO2 and ETO2 detection, respectively. A small sample gas volume of 2.6 mL enables a rapid response time of <0.5 s, enabling rapid tracking of changes in exhaled gas concentration. The optimized system achieves detection limits of 12.6 ppm for CO2 and 18.4 ppm for O2, with corresponding normalized noise equivalent absorption values of 2.9 × 10−8 and 1.6 × 10−7 cm−1⋅W⋅Hz−1/2. Real-time monitoring during human respiration demonstrates clear tracking of physiological O2 depletion and CO2 enrichment, consistent with respiratory dynamics. The developed sensor combines high sensitivity, fast response, compact size, and low cost, showing strong potential for continuous clinical monitoring, perioperative care, and metabolic studies.
{"title":"Compact Differential Photoacoustic Exhaled Gas Sensor for Online ETCO2 and ETO2 Monitoring","authors":"Xukun Yin, Chenchen Zhu, Xiu Yang, Lei Liu, Dacheng Zhang, Kaijie Xu, Hongzhi Wang, Shuangping Zhang, Nicoletta Ardito, Pietro Patimisco, Angelo Sampaolo, Vincenzo Spagnolo, Hongpeng Wu, Huailiang Xu","doi":"10.1021/acssensors.5c03835","DOIUrl":"https://doi.org/10.1021/acssensors.5c03835","url":null,"abstract":"Online exhaled breath analysis holds great promise for noninvasive medical diagnostics, health monitoring, and environmental exposure assessment. However, the complex nature of the breath matrix and strong interference from water vapor and carbon dioxide make high-precision, real-time sensing challenging, often requiring large and costly systems such as mass spectrometers. In this work, we present a compact differential photoacoustic gas sensor for end-tidal carbon dioxide (ETCO<sub>2</sub>) and end-tidal oxygen (ETO<sub>2</sub>) monitoring. The sensor employs a dual-resonator photoacoustic cell with resonant frequencies of 4110 and 13,115 Hz for selective ETCO<sub>2</sub> and ETO<sub>2</sub> detection, respectively. A small sample gas volume of 2.6 mL enables a rapid response time of <0.5 s, enabling rapid tracking of changes in exhaled gas concentration. The optimized system achieves detection limits of 12.6 ppm for CO<sub>2</sub> and 18.4 ppm for O<sub>2</sub>, with corresponding normalized noise equivalent absorption values of 2.9 × 10<sup>−8</sup> and 1.6 × 10<sup>−7</sup> cm<sup>−1</sup>⋅W⋅Hz<sup>−1/2</sup>. Real-time monitoring during human respiration demonstrates clear tracking of physiological O<sub>2</sub> depletion and CO<sub>2</sub> enrichment, consistent with respiratory dynamics. The developed sensor combines high sensitivity, fast response, compact size, and low cost, showing strong potential for continuous clinical monitoring, perioperative care, and metabolic studies.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"44 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monolayer noble metal nanoparticle (NP) arrays hold great promise as surface-enhanced Raman scattering (SERS) substrates due to their strong SERS performance and cost-effectiveness. However, precise regulation of hotspot intensity and density remains a critical challenge for practical applications. Here, we propose a SERS substrate based on Janus-structure NPs, which realizes accessible metal-semiconductor interface hotspots, as well as the regulation of interparticle nanogaps of ∼1 nm through a multifunctional surface ligand. By selectively depositing cerium oxide (CeO2) onto one terminus of gold nanorods (Au NRs), we fabricate Janus nanostructures that generate highly accessible and intensified hotspots. Another key enabler of this advancement is 4-mercaptophenylboronic acid (MPBA), a multifunctional ligand that precisely regulates interparticle spacing, increases hotspot density, and simultaneously serves as both a Raman molecule and a bacterial recognition unit. The SERS enhancement effect of the Janus NP array can reach more than 11 times that of the conventional Au NR array. Based on this MPBA-functionalized Janus NP array substrate, a SERS sensor for Escherichia coli was constructed, which exhibited a robust linear detection response to bacterial concentrations ranging from 6 to 6 × 104 CFU/μL, with an ultralow detection limit of approximately 1.1 CFU/μL. Our work introduces a versatile strategy for next-generation SERS substrates.
{"title":"Interface-Engineered Janus Au@CeO2 Nanostructures for Ultrasensitive Ratiometric SERS Platforms.","authors":"Lulu Tian,Songtao Hu,Qihang Ding,Zhenyu Ma,Cong Chen,Chunyan Li,Kun Wang,Juanrui Du,Yujia Shi,Jong Seung Kim,Lin Wang,Biao Dong","doi":"10.1021/acssensors.5c03379","DOIUrl":"https://doi.org/10.1021/acssensors.5c03379","url":null,"abstract":"Monolayer noble metal nanoparticle (NP) arrays hold great promise as surface-enhanced Raman scattering (SERS) substrates due to their strong SERS performance and cost-effectiveness. However, precise regulation of hotspot intensity and density remains a critical challenge for practical applications. Here, we propose a SERS substrate based on Janus-structure NPs, which realizes accessible metal-semiconductor interface hotspots, as well as the regulation of interparticle nanogaps of ∼1 nm through a multifunctional surface ligand. By selectively depositing cerium oxide (CeO2) onto one terminus of gold nanorods (Au NRs), we fabricate Janus nanostructures that generate highly accessible and intensified hotspots. Another key enabler of this advancement is 4-mercaptophenylboronic acid (MPBA), a multifunctional ligand that precisely regulates interparticle spacing, increases hotspot density, and simultaneously serves as both a Raman molecule and a bacterial recognition unit. The SERS enhancement effect of the Janus NP array can reach more than 11 times that of the conventional Au NR array. Based on this MPBA-functionalized Janus NP array substrate, a SERS sensor for Escherichia coli was constructed, which exhibited a robust linear detection response to bacterial concentrations ranging from 6 to 6 × 104 CFU/μL, with an ultralow detection limit of approximately 1.1 CFU/μL. Our work introduces a versatile strategy for next-generation SERS substrates.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"64 1","pages":"XXX"},"PeriodicalIF":8.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146056365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
African swine fever virus (ASFV) causes devastating outbreaks in swine populations worldwide. The co-existence of wild-type and emerging gene-deleted variants (e.g., ASFV-ΔI177L) necessitates rapid on-site diagnostic tools for strain identification, which is critical for timely disease control and tailored farm management. Here, we developed a field-deployable, extraction-free one-pot assay (CORDSv2) that combines multiplex RPA and CRISPR/Cas12a to target conserved ASFV sequences and specific fluorescent markers (eGFP/mCherry) of gene-deleted variants. The assay achieved ultrasensitive detection (LOD: 6 copies/μL) and demonstrated 97.9% accuracy with 96 field samples. To streamline field operations, we integrated an extraction-free protocol (for serum/saliva) with freeze-dried reagent microspheres, enabling stable storage and direct use with minimal manual handling. When paired with a portable fluorometer (hippoCORDS), the system completes the entire sample-to-answer workflow within 1 h with a single step: addition of lysate to the microspheres. This robust, portable system addresses the urgent need for simple, on-site ASFV variant surveillance and is adaptable for other high-threat pathogens.
{"title":"An Extraction-free One-Pot Assay for Rapid Field Discrimination of African Swine Fever Virus Variants by a Single-Step RPA-CRISPR/Cas12a Strategy.","authors":"Wenyan Li,Yunpeng Yang,Wenyi Xu,Yongchong Zhu,Yue Li,Lihui Cao,Shuyao Lyu,Jingqun Liu,Yan Xie,Xueping Li,Xianghua Hu,Lizhen Huang","doi":"10.1021/acssensors.5c03287","DOIUrl":"https://doi.org/10.1021/acssensors.5c03287","url":null,"abstract":"African swine fever virus (ASFV) causes devastating outbreaks in swine populations worldwide. The co-existence of wild-type and emerging gene-deleted variants (e.g., ASFV-ΔI177L) necessitates rapid on-site diagnostic tools for strain identification, which is critical for timely disease control and tailored farm management. Here, we developed a field-deployable, extraction-free one-pot assay (CORDSv2) that combines multiplex RPA and CRISPR/Cas12a to target conserved ASFV sequences and specific fluorescent markers (eGFP/mCherry) of gene-deleted variants. The assay achieved ultrasensitive detection (LOD: 6 copies/μL) and demonstrated 97.9% accuracy with 96 field samples. To streamline field operations, we integrated an extraction-free protocol (for serum/saliva) with freeze-dried reagent microspheres, enabling stable storage and direct use with minimal manual handling. When paired with a portable fluorometer (hippoCORDS), the system completes the entire sample-to-answer workflow within 1 h with a single step: addition of lysate to the microspheres. This robust, portable system addresses the urgent need for simple, on-site ASFV variant surveillance and is adaptable for other high-threat pathogens.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"110 1","pages":"XXX"},"PeriodicalIF":8.9,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146056942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-22DOI: 10.1021/acssensors.5c03192
Yingying Feng,Wanqi Jiang,Wenya Liu,Yuqing Zhang,Xiyao Liang,Shuqing Mei,Kai Wang,Yaqing Xiao,Yingnan Liu
A portable integrated sensing device incorporating a Tb3+/DTE-Cu NC ratiometric fluorescent probe was developed for the rapid on-site detection of fluoroquinolone (FQ) residues in poultry eggs. The system features a dual-layer filtration unit, consisting of glass wool and a polyvinyl alcohol/sodium alginate hydrogel, which purifies egg samples in situ through combined physical interception and chemical adsorption. The Tb3+/DTE-Cu NC probe was immobilized within the hydrogel matrix, enabling full integration of the entire "sample introduction-filtration-detection" process. Under 365 nm UV light, fluorescence emission shifts from red to green as the FQ concentration increases. Quantitative analysis is accomplished by extracting the G/R ratio from smartphone-captured RGB values. The device achieves a detection limit of 1.6 nM, with recoveries for spiked egg samples ranging from 91% to 112%. This low-cost, rapid, and instrument-free platform presents a practical solution for the sensitive on-site monitoring of antibiotic residues in food safety applications.
{"title":"One-Click Egg Safety Check: A Syringe-Integrated Portable Platform for On-Site Fluoroquinolone Residue Detection.","authors":"Yingying Feng,Wanqi Jiang,Wenya Liu,Yuqing Zhang,Xiyao Liang,Shuqing Mei,Kai Wang,Yaqing Xiao,Yingnan Liu","doi":"10.1021/acssensors.5c03192","DOIUrl":"https://doi.org/10.1021/acssensors.5c03192","url":null,"abstract":"A portable integrated sensing device incorporating a Tb3+/DTE-Cu NC ratiometric fluorescent probe was developed for the rapid on-site detection of fluoroquinolone (FQ) residues in poultry eggs. The system features a dual-layer filtration unit, consisting of glass wool and a polyvinyl alcohol/sodium alginate hydrogel, which purifies egg samples in situ through combined physical interception and chemical adsorption. The Tb3+/DTE-Cu NC probe was immobilized within the hydrogel matrix, enabling full integration of the entire \"sample introduction-filtration-detection\" process. Under 365 nm UV light, fluorescence emission shifts from red to green as the FQ concentration increases. Quantitative analysis is accomplished by extracting the G/R ratio from smartphone-captured RGB values. The device achieves a detection limit of 1.6 nM, with recoveries for spiked egg samples ranging from 91% to 112%. This low-cost, rapid, and instrument-free platform presents a practical solution for the sensitive on-site monitoring of antibiotic residues in food safety applications.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"37 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146015176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-22DOI: 10.1021/acssensors.5c02217
Ke Chen,Guozhu Zhang,Rui Gao,Jiangfei Shi,Chao Zhang,Zeyu Wang,Kun Qian,Kazuki Nagashima,Yang Gao,Fu-Zhen Xuan
Highly active and stable sensing surfaces are critical for the integration of catalysis-based electrical gas molecular sensors. However, achieving both high sensitivity and durability remains a persistent challenge due to continuous exposure to target molecules often results in surface deactivation and sensing performance degradation. Herein, we demonstrate a robust surface functionalization strategy to simultaneously enhance sensitivity and long-term stability for ammonia (NH3) detection by modifying hexagonal tungsten oxide (h-WO3) nanowires with methylphosphonic acid (MPA). Fourier-transform infrared spectroscopy (FTIR) and density functional theory (DFT) calculations reveal that phosphate groups in MPA selectively bind to the Lewis acid sites (undercoordinated W6+) on h-WO3 nanowires, effectively passivating the surface and mitigating degradation. Concurrently, the electron-rich P=O moiety facilitates strong interaction with NH3 molecules, leading to enhanced chemisorption and signal transduction. As a result, MPA-functionalized h-WO3 nanowire sensors exhibit a nearly tenfold increase in NH3 sensitivity compared to the unmodified h-WO3 sensors and maintain stable performance over 300 days of continuous operation. As a proof of concept for applied scenarios, we integrate the modified sensors into a microelectromechanical system (MEMS)-based smart ventilation system, enabling real-time NH3 monitoring and control in livestock environments. This work presents a viable route for designing high-performance, durable gas sensors through targeted molecular surface engineering.
{"title":"Phosphonic Acid-Anchored Tungsten Oxide Nanowire with Boosted Activity and Stability for Ammonia Sensing.","authors":"Ke Chen,Guozhu Zhang,Rui Gao,Jiangfei Shi,Chao Zhang,Zeyu Wang,Kun Qian,Kazuki Nagashima,Yang Gao,Fu-Zhen Xuan","doi":"10.1021/acssensors.5c02217","DOIUrl":"https://doi.org/10.1021/acssensors.5c02217","url":null,"abstract":"Highly active and stable sensing surfaces are critical for the integration of catalysis-based electrical gas molecular sensors. However, achieving both high sensitivity and durability remains a persistent challenge due to continuous exposure to target molecules often results in surface deactivation and sensing performance degradation. Herein, we demonstrate a robust surface functionalization strategy to simultaneously enhance sensitivity and long-term stability for ammonia (NH3) detection by modifying hexagonal tungsten oxide (h-WO3) nanowires with methylphosphonic acid (MPA). Fourier-transform infrared spectroscopy (FTIR) and density functional theory (DFT) calculations reveal that phosphate groups in MPA selectively bind to the Lewis acid sites (undercoordinated W6+) on h-WO3 nanowires, effectively passivating the surface and mitigating degradation. Concurrently, the electron-rich P=O moiety facilitates strong interaction with NH3 molecules, leading to enhanced chemisorption and signal transduction. As a result, MPA-functionalized h-WO3 nanowire sensors exhibit a nearly tenfold increase in NH3 sensitivity compared to the unmodified h-WO3 sensors and maintain stable performance over 300 days of continuous operation. As a proof of concept for applied scenarios, we integrate the modified sensors into a microelectromechanical system (MEMS)-based smart ventilation system, enabling real-time NH3 monitoring and control in livestock environments. This work presents a viable route for designing high-performance, durable gas sensors through targeted molecular surface engineering.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"103 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146015177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-22DOI: 10.1021/acssensors.5c03836
Shaorui Qi,Lei Sun,Fansheng Meng,Guimei Shi,Yunlong Sun,Bo Jiang,Junbo Li,Yukihiro Ozaki,Wei Ji
Abnormal lactic acid (LA) enantiomeric excess (ee) in biofluids is closely associated with various intestinal diseases. Here, we report a chiral-label-free nonplasmonic surface-enhanced Raman scattering (SERS) platform using a ZIF-8/ZnS heterojunction that enables direct quantification of LA enantiomers and their ee values in raw human urine through a charge-transfer-driven chiral recognition mechanism. Our findings indicate that an enantioselective hydrogen bonding between 4-mercaptopyridine (4-MPy) probes and LA enantiomers induces differential charge-transfer effects within the ZIF-8/ZnS@4-MPy system, evidenced by the selective enhancement of specific vibrational modes in the SERS spectra of 4-MPy and enantiomer-specific changes in the fluorescence lifetime of ZnS. This innovative system integrates signal amplification and stereoselectivity without the use of noble metals or chiral modifiers, overcoming critical limitations associated with the complexity of preparing chiral plasmonic substrates. The platform achieves ultrasensitive detection limits (10 nM), linear response to ee values (R2 = 0.98), high measurement precision (RSD < 8.28%, n = 20), long-term stability (28-day), and clinical-grade accuracy against enzymatic assays (RMSEP = 1.97). This work presents an efficient, noninvasive method for the analysis of chiral metabolites in urine, while establishing a novel direction for plasmon-free SERS chiral sensing.
{"title":"Charge-Transfer-Driven Enantioselective Surface-Enhanced Raman Scattering on a ZIF-8/ZnS Heterojunction: A Chiral-Label-Free Biosensor for Quantification of Urinary Lactate Enantiomeric Excess.","authors":"Shaorui Qi,Lei Sun,Fansheng Meng,Guimei Shi,Yunlong Sun,Bo Jiang,Junbo Li,Yukihiro Ozaki,Wei Ji","doi":"10.1021/acssensors.5c03836","DOIUrl":"https://doi.org/10.1021/acssensors.5c03836","url":null,"abstract":"Abnormal lactic acid (LA) enantiomeric excess (ee) in biofluids is closely associated with various intestinal diseases. Here, we report a chiral-label-free nonplasmonic surface-enhanced Raman scattering (SERS) platform using a ZIF-8/ZnS heterojunction that enables direct quantification of LA enantiomers and their ee values in raw human urine through a charge-transfer-driven chiral recognition mechanism. Our findings indicate that an enantioselective hydrogen bonding between 4-mercaptopyridine (4-MPy) probes and LA enantiomers induces differential charge-transfer effects within the ZIF-8/ZnS@4-MPy system, evidenced by the selective enhancement of specific vibrational modes in the SERS spectra of 4-MPy and enantiomer-specific changes in the fluorescence lifetime of ZnS. This innovative system integrates signal amplification and stereoselectivity without the use of noble metals or chiral modifiers, overcoming critical limitations associated with the complexity of preparing chiral plasmonic substrates. The platform achieves ultrasensitive detection limits (10 nM), linear response to ee values (R2 = 0.98), high measurement precision (RSD < 8.28%, n = 20), long-term stability (28-day), and clinical-grade accuracy against enzymatic assays (RMSEP = 1.97). This work presents an efficient, noninvasive method for the analysis of chiral metabolites in urine, while establishing a novel direction for plasmon-free SERS chiral sensing.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"25 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146015175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Achieving quantitative and reproducible surface-enhanced Raman scattering (SERS) detection remains challenging due to the stochastic nature of molecular distribution and the nonuniform enhancement of localized plasmonic "hot spots". Here, we present a wettability-patterned Ag nanoparticles and ZnO nanorod (Ag/ZnO)-nanostructured substrate that enables self-metered droplet partitioning and uniform molecular deposition for quantitative SERS sensing. By exploiting the strong contrast between hydrophilic and hydrophobic regions, a bulk liquid droplet can spontaneously split into an array of equal-volume microdroplets without any external confinement. During evaporation, the hydrophilic Ag/ZnO nanocolumns induce capillary-driven infiltration, which, in combination with wettability confinement, effectively suppresses the coffee ring effect and ensures homogeneous solute deposition within a defined area. Systematic comparisons among hydrophilic, flat-patterned, and nanostructured-patterned substrates reveal distinct drying dynamics, confirming that the synergistic control of capillary infiltration and wettability patterning governs uniform analyte distribution. Consequently, the designed substrate delivers highly linear and reproducible (RSD < 5%) SERS responses across multiple domains and analyte types. This simple yet robust self-metered droplet strategy provides a practical route toward uniform, quantitative, and molecule-independent SERS detection, offering new opportunities for reliable chemical and biosensing applications.
{"title":"Self-Metered and Uniform Droplet Deposition within Defined Areas for Quantitative Surface-Enhanced Raman Scattering Detection.","authors":"Zhilin Feng,Zhenle Qin,Xiaohui Fang,Yang Li,He Ma,Xinping Zhang","doi":"10.1021/acssensors.5c04445","DOIUrl":"https://doi.org/10.1021/acssensors.5c04445","url":null,"abstract":"Achieving quantitative and reproducible surface-enhanced Raman scattering (SERS) detection remains challenging due to the stochastic nature of molecular distribution and the nonuniform enhancement of localized plasmonic \"hot spots\". Here, we present a wettability-patterned Ag nanoparticles and ZnO nanorod (Ag/ZnO)-nanostructured substrate that enables self-metered droplet partitioning and uniform molecular deposition for quantitative SERS sensing. By exploiting the strong contrast between hydrophilic and hydrophobic regions, a bulk liquid droplet can spontaneously split into an array of equal-volume microdroplets without any external confinement. During evaporation, the hydrophilic Ag/ZnO nanocolumns induce capillary-driven infiltration, which, in combination with wettability confinement, effectively suppresses the coffee ring effect and ensures homogeneous solute deposition within a defined area. Systematic comparisons among hydrophilic, flat-patterned, and nanostructured-patterned substrates reveal distinct drying dynamics, confirming that the synergistic control of capillary infiltration and wettability patterning governs uniform analyte distribution. Consequently, the designed substrate delivers highly linear and reproducible (RSD < 5%) SERS responses across multiple domains and analyte types. This simple yet robust self-metered droplet strategy provides a practical route toward uniform, quantitative, and molecule-independent SERS detection, offering new opportunities for reliable chemical and biosensing applications.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"31 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146015178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Semiconductor gas sensors are widely used in environmental monitoring, industrial safety, etc., yet their performance is often hindered by issues such as cross-response, poor stability, and low sensitivity. Given the material-dependent nature of these limitations, the targeted optimization of the sensing properties remains a core challenge in the field. Gas sensing primarily involves adsorption and surface reactions, with performance critically governed by interfacial reaction kinetics at the gas-semiconductor interface. A deep understanding and precise modulation of these interfacial mechanisms are therefore essential for performance enhancement. This review systematically discusses how interfacial reactions influence key sensing parameters, including sensitivity, selectivity, stability, and dynamic response. Strategies for regulating these interfacial processes are analyzed to inform the rational design of high-performance sensors. Additionally, state-of-the-art characterization techniques and theoretical approaches for probing interfacial mechanisms are summarized, offering technical support for elucidating microscopic reaction pathways. By integrating current advances and challenges, this review establishes the fundamental links between material properties, interfacial chemistry, and sensing behavior, thereby providing a theoretical framework and design guidance for the next-generation semiconductor gas sensors.
{"title":"Performance Optimization of Semiconductor Gas Sensors Based on Interfacial Reaction Regulation: Status and Challenges.","authors":"Xinyi Dai,Yuting Zhu,Sibo Zhang,Pengfei Sun,Xiaoping Dong,Fan Dong,Si Chen","doi":"10.1021/acssensors.5c02681","DOIUrl":"https://doi.org/10.1021/acssensors.5c02681","url":null,"abstract":"Semiconductor gas sensors are widely used in environmental monitoring, industrial safety, etc., yet their performance is often hindered by issues such as cross-response, poor stability, and low sensitivity. Given the material-dependent nature of these limitations, the targeted optimization of the sensing properties remains a core challenge in the field. Gas sensing primarily involves adsorption and surface reactions, with performance critically governed by interfacial reaction kinetics at the gas-semiconductor interface. A deep understanding and precise modulation of these interfacial mechanisms are therefore essential for performance enhancement. This review systematically discusses how interfacial reactions influence key sensing parameters, including sensitivity, selectivity, stability, and dynamic response. Strategies for regulating these interfacial processes are analyzed to inform the rational design of high-performance sensors. Additionally, state-of-the-art characterization techniques and theoretical approaches for probing interfacial mechanisms are summarized, offering technical support for elucidating microscopic reaction pathways. By integrating current advances and challenges, this review establishes the fundamental links between material properties, interfacial chemistry, and sensing behavior, thereby providing a theoretical framework and design guidance for the next-generation semiconductor gas sensors.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"88 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146005310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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