Pub Date : 2025-03-10DOI: 10.1021/acssensors.4c0294610.1021/acssensors.4c02946
Navpreet Kaur*,
The need for efficient and reliable gas sensors has grown significantly due to increasing industrial activities, transportation, and environmental pollution, posing serious risks to human health and the environment. Advanced sensor technologies are crucial for detecting these harmful gases at low concentrations with a high accuracy. Nickel oxide, a p-type metal oxide semiconductor, has emerged as a promising candidate for gas sensing applications owing to its unique and excellent structural, electronic, and catalytic properties along with its high chemical stability. Interestingly, the possibility to synthesize NiO in versatile nanostructure forms: nanowires, nanoflowers, and nanospheres, helps to enhance surface area and porosity, which are critical factors to improve gas adsorption and diffusion. This review presents a comprehensive and critical assessment of the latest advancements in the synthesis, characterization, and gas-sensing performance of NiO nanostructures. We explore how structural modifications, such as decoration with noble metal nanoparticles, formation of different composites, and surface functionalization with self-assembly enhance the sensitivity, selectivity, and operational temperature of NiO sensors. Particular focus is given to the integration of NiO in novel nanoheterostructures, where the formation of p-n and p-p junctions significantly improves charge transport and overall sensor response. Finally, we identify current challenges in reproducibility, stability, and operating conditions, while offering directions for future research on tailoring NiO nanostructures for more effective, scalable, and robust sensor technologies.
{"title":"Nickel Oxide Nanostructures for Gas Sensing: Recent Advances, Challenges, and Future Perspectives","authors":"Navpreet Kaur*, ","doi":"10.1021/acssensors.4c0294610.1021/acssensors.4c02946","DOIUrl":"https://doi.org/10.1021/acssensors.4c02946https://doi.org/10.1021/acssensors.4c02946","url":null,"abstract":"<p >The need for efficient and reliable gas sensors has grown significantly due to increasing industrial activities, transportation, and environmental pollution, posing serious risks to human health and the environment. Advanced sensor technologies are crucial for detecting these harmful gases at low concentrations with a high accuracy. Nickel oxide, a p-type metal oxide semiconductor, has emerged as a promising candidate for gas sensing applications owing to its unique and excellent structural, electronic, and catalytic properties along with its high chemical stability. Interestingly, the possibility to synthesize NiO in versatile nanostructure forms: nanowires, nanoflowers, and nanospheres, helps to enhance surface area and porosity, which are critical factors to improve gas adsorption and diffusion. This review presents a comprehensive and critical assessment of the latest advancements in the synthesis, characterization, and gas-sensing performance of NiO nanostructures. We explore how structural modifications, such as decoration with noble metal nanoparticles, formation of different composites, and surface functionalization with self-assembly enhance the sensitivity, selectivity, and operational temperature of NiO sensors. Particular focus is given to the integration of NiO in novel nanoheterostructures, where the formation of p-n and p-p junctions significantly improves charge transport and overall sensor response. Finally, we identify current challenges in reproducibility, stability, and operating conditions, while offering directions for future research on tailoring NiO nanostructures for more effective, scalable, and robust sensor technologies.</p>","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"10 3","pages":"1641–1674 1641–1674"},"PeriodicalIF":8.2,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713837","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}
Wearable gas sensors offer remarkable advantages in terms of portability and real-time monitoring, rendering them highly promising for various applications such as environmental detection, health monitoring, and early disease diagnosis. However, the most widely used oxide semiconductor gas sensors encounter substantial challenges in achieving mechanical flexibility and room-temperature gas detection due to their inherent rigidity, brittleness, and reliance on high operating temperatures. Herein, an all-inorganic wearable oxide semiconductor gas sensor is fabricated by depositing the anatase/rutile TiO2 (TiO2-A/R) homojunction on a flexible yttria-stabilized zirconia (YSZ) nanofiber substrate using atomic layer deposition technology. The combination of the YSZ nanofiber and the ultrathin TiO2 sensing layer (∼13 nm) endows the wearable sensor with tiny linear strains (0.55%) when subjected to a radius of curvature of 25 μm. As a result, the wearable inorganic YSZ/TiO2-A/R sensor can be folded multiple times without fracturing and maintain a stable electrical connectivity during cyclic bending. Furthermore, the utilization of photoactive TiO2 homojunctions allows the sensor to be activated by UV light and operated at room temperature. The efficient separation efficiency of photogenerated carriers, which stems from the interfacial electric field of TiO2 homojunctions, significantly enhances the sensor’s response, leading to a low detection limit of 0.15 ppm for acetone. In addition, the wearable sensor was anchored on a mask and successfully utilized for the detection of a simulated breathing gas of diabetics; the real-time and stable response signals demonstrate its potential for noninvasive diabetes diagnosis. This study provides a valuable reference for the advancement of wearable room-temperature inorganic semiconductor gas sensors, offering valuable insights into their potential applications in disease diagnosis.
{"title":"Room-Temperature Wearable Chemiresistor Based on a Flexible Inorganic Photoactive Anatase–Rutile TiO2/Yttria-Stabilized Zirconia Nanofiber Network","authors":"Wanying Cheng, Xiaowei Li, Chaohan Han, Yu Liu, Aoqun Xue, Haipeng Dong, Xinghua Li, Changlu Shao, Yichun Liu","doi":"10.1021/acssensors.4c03380","DOIUrl":"https://doi.org/10.1021/acssensors.4c03380","url":null,"abstract":"Wearable gas sensors offer remarkable advantages in terms of portability and real-time monitoring, rendering them highly promising for various applications such as environmental detection, health monitoring, and early disease diagnosis. However, the most widely used oxide semiconductor gas sensors encounter substantial challenges in achieving mechanical flexibility and room-temperature gas detection due to their inherent rigidity, brittleness, and reliance on high operating temperatures. Herein, an all-inorganic wearable oxide semiconductor gas sensor is fabricated by depositing the anatase/rutile TiO<sub>2</sub> (TiO<sub>2</sub>-A/R) homojunction on a flexible yttria-stabilized zirconia (YSZ) nanofiber substrate using atomic layer deposition technology. The combination of the YSZ nanofiber and the ultrathin TiO<sub>2</sub> sensing layer (∼13 nm) endows the wearable sensor with tiny linear strains (0.55%) when subjected to a radius of curvature of 25 μm. As a result, the wearable inorganic YSZ/TiO<sub>2</sub>-A/R sensor can be folded multiple times without fracturing and maintain a stable electrical connectivity during cyclic bending. Furthermore, the utilization of photoactive TiO<sub>2</sub> homojunctions allows the sensor to be activated by UV light and operated at room temperature. The efficient separation efficiency of photogenerated carriers, which stems from the interfacial electric field of TiO<sub>2</sub> homojunctions, significantly enhances the sensor’s response, leading to a low detection limit of 0.15 ppm for acetone. In addition, the wearable sensor was anchored on a mask and successfully utilized for the detection of a simulated breathing gas of diabetics; the real-time and stable response signals demonstrate its potential for noninvasive diabetes diagnosis. This study provides a valuable reference for the advancement of wearable room-temperature inorganic semiconductor gas sensors, offering valuable insights into their potential applications in disease diagnosis.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"56 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143590067","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 : 2025-03-10DOI: 10.1021/acssensors.5c00135
Dan Li, Ruilong Dai, Shangjun Chen, Juan Li, Jiamei Chen, Chenxu Yan, Zhiqian Guo
High-fidelity tracking of glycogen dynamics in living biosystems is critical for exploring the biological role of glycogen metabolism in diseases. However, in situ information on the glycogen state mainly relies on a glucose uptake fluorescence probe 2-NBDG, which has proven to be extremely limited owing to the “always-on” fluorescence, short emission wavelength, and low signal-to-noise (S/N) ratio. Herein, we for the first time demonstrate a metabolic-activated off–on probe for glycogen through covalently attaching a molecular rotor with hydrophilic glucose at the C-2 position to guarantee good miscibility with a complete fluorescence-off state before metabolic incorporation into glycogen particles. The probe Glycogen-Red achieves negligible background fluorescence (1/30 times than 2-NBDG) and an ultrahigh S/N ratio (61-fold than 2-NBDG) of lighting-up near-infrared (NIR) fluorescence in glycogen biosynthesis. Notably, our probe has the unique characteristic of bypassing the washing steps, offering a powerful toolbox for real-time tracking of glycogen biosynthesis and super-resolution mapping of glycogen structures in living cells.
{"title":"In Situ Lighting-Up Near-Infrared Metabolic Probes for Super-Resolution Imaging of Glycogen","authors":"Dan Li, Ruilong Dai, Shangjun Chen, Juan Li, Jiamei Chen, Chenxu Yan, Zhiqian Guo","doi":"10.1021/acssensors.5c00135","DOIUrl":"https://doi.org/10.1021/acssensors.5c00135","url":null,"abstract":"High-fidelity tracking of glycogen dynamics in living biosystems is critical for exploring the biological role of glycogen metabolism in diseases. However, <i>in situ</i> information on the glycogen state mainly relies on a glucose uptake fluorescence probe 2-NBDG, which has proven to be extremely limited owing to the “always-on” fluorescence, short emission wavelength, and low signal-to-noise (S/N) ratio. Herein, we for the first time demonstrate a metabolic-activated off–on probe for glycogen through covalently attaching a molecular rotor with hydrophilic glucose at the C-2 position to guarantee good miscibility with a complete fluorescence-off state before metabolic incorporation into glycogen particles. The probe Glycogen-Red achieves negligible background fluorescence (1/30 times than 2-NBDG) and an ultrahigh S/N ratio (61-fold than 2-NBDG) of lighting-up near-infrared (NIR) fluorescence in glycogen biosynthesis. Notably, our probe has the unique characteristic of bypassing the washing steps, offering a powerful toolbox for real-time tracking of glycogen biosynthesis and super-resolution mapping of glycogen structures in living cells.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"14 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143590069","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 : 2025-03-10DOI: 10.1021/acssensors.5c0018710.1021/acssensors.5c00187
Hao Zhang, Chunqing Yang, Hui Xia, Wenzheng An, Mingyu Qi and Dongzhi Zhang*,
With the rapid emergence of flexible electronics, flexible pressure sensors are of importance in various fields. In this study, a dopamine-modified melamine sponge (MS) was used to prepare a honeycomb structure of carbon black (CB)/MXene-silicone rubber (SR)@MS flexible pressure sensor (CMSM) through layer-by-layer self-assembly technology. Using SR as a binder to construct the honeycomb structure not only improves the mechanical properties of the sensor but also provides more attachment sites for CB/MXene, enhancing the stability of the conductive network. The honeycomb structure CMSM flexible pressure sensor exhibits high sensitivity (7.44 kPa–1), a wide detection range (0–240 kPa), short response/recovery times (150 ms/180 ms), and exhibits excellent stability. In addition, a flexible smart insole has been developed based on a 6-unit CMSM sensor array, achieving plantar pressure detection. By combination of the ResNet-50 neural network algorithm with plantar pressure data under different postures, the recognition of 16 types of human motion postures has been achieved, with an accuracy rate of 90.63%. This study proposes a flexible sponge pressure sensor with excellent mechanical performance and sensing capabilities, providing new ideas and references for the design of flexible wearable sensor devices.
{"title":"Layer-by-Layer Self-Assembled Honeycomb Structure Flexible Pressure Sensor Array for Gait Analysis and Motion Posture Recognition with the Assistance of the ResNet-50 Neural Network","authors":"Hao Zhang, Chunqing Yang, Hui Xia, Wenzheng An, Mingyu Qi and Dongzhi Zhang*, ","doi":"10.1021/acssensors.5c0018710.1021/acssensors.5c00187","DOIUrl":"https://doi.org/10.1021/acssensors.5c00187https://doi.org/10.1021/acssensors.5c00187","url":null,"abstract":"<p >With the rapid emergence of flexible electronics, flexible pressure sensors are of importance in various fields. In this study, a dopamine-modified melamine sponge (MS) was used to prepare a honeycomb structure of carbon black (CB)/MXene-silicone rubber (SR)@MS flexible pressure sensor (CMSM) through layer-by-layer self-assembly technology. Using SR as a binder to construct the honeycomb structure not only improves the mechanical properties of the sensor but also provides more attachment sites for CB/MXene, enhancing the stability of the conductive network. The honeycomb structure CMSM flexible pressure sensor exhibits high sensitivity (7.44 kPa<sup>–1</sup>), a wide detection range (0–240 kPa), short response/recovery times (150 ms/180 ms), and exhibits excellent stability. In addition, a flexible smart insole has been developed based on a 6-unit CMSM sensor array, achieving plantar pressure detection. By combination of the ResNet-50 neural network algorithm with plantar pressure data under different postures, the recognition of 16 types of human motion postures has been achieved, with an accuracy rate of 90.63%. This study proposes a flexible sponge pressure sensor with excellent mechanical performance and sensing capabilities, providing new ideas and references for the design of flexible wearable sensor devices.</p>","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"10 3","pages":"2358–2366 2358–2366"},"PeriodicalIF":8.2,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714163","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 : 2025-03-10DOI: 10.1021/acssensors.4c02946
Navpreet Kaur
The need for efficient and reliable gas sensors has grown significantly due to increasing industrial activities, transportation, and environmental pollution, posing serious risks to human health and the environment. Advanced sensor technologies are crucial for detecting these harmful gases at low concentrations with a high accuracy. Nickel oxide, a p-type metal oxide semiconductor, has emerged as a promising candidate for gas sensing applications owing to its unique and excellent structural, electronic, and catalytic properties along with its high chemical stability. Interestingly, the possibility to synthesize NiO in versatile nanostructure forms: nanowires, nanoflowers, and nanospheres, helps to enhance surface area and porosity, which are critical factors to improve gas adsorption and diffusion. This review presents a comprehensive and critical assessment of the latest advancements in the synthesis, characterization, and gas-sensing performance of NiO nanostructures. We explore how structural modifications, such as decoration with noble metal nanoparticles, formation of different composites, and surface functionalization with self-assembly enhance the sensitivity, selectivity, and operational temperature of NiO sensors. Particular focus is given to the integration of NiO in novel nanoheterostructures, where the formation of p-n and p-p junctions significantly improves charge transport and overall sensor response. Finally, we identify current challenges in reproducibility, stability, and operating conditions, while offering directions for future research on tailoring NiO nanostructures for more effective, scalable, and robust sensor technologies.
{"title":"Nickel Oxide Nanostructures for Gas Sensing: Recent Advances, Challenges, and Future Perspectives","authors":"Navpreet Kaur","doi":"10.1021/acssensors.4c02946","DOIUrl":"https://doi.org/10.1021/acssensors.4c02946","url":null,"abstract":"The need for efficient and reliable gas sensors has grown significantly due to increasing industrial activities, transportation, and environmental pollution, posing serious risks to human health and the environment. Advanced sensor technologies are crucial for detecting these harmful gases at low concentrations with a high accuracy. Nickel oxide, a p-type metal oxide semiconductor, has emerged as a promising candidate for gas sensing applications owing to its unique and excellent structural, electronic, and catalytic properties along with its high chemical stability. Interestingly, the possibility to synthesize NiO in versatile nanostructure forms: nanowires, nanoflowers, and nanospheres, helps to enhance surface area and porosity, which are critical factors to improve gas adsorption and diffusion. This review presents a comprehensive and critical assessment of the latest advancements in the synthesis, characterization, and gas-sensing performance of NiO nanostructures. We explore how structural modifications, such as decoration with noble metal nanoparticles, formation of different composites, and surface functionalization with self-assembly enhance the sensitivity, selectivity, and operational temperature of NiO sensors. Particular focus is given to the integration of NiO in novel nanoheterostructures, where the formation of p-n and p-p junctions significantly improves charge transport and overall sensor response. Finally, we identify current challenges in reproducibility, stability, and operating conditions, while offering directions for future research on tailoring NiO nanostructures for more effective, scalable, and robust sensor technologies.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"8 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582517","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 : 2025-03-09DOI: 10.1021/acssensors.4c02913
Soumita Maiti, Milad Taghavi, Parag Chaudhari, Sangchul Roh, Itai Cohen, Alyssa B. Apsel, Nicholas L. Abbott
The surface-induced ordering of liquid crystals (LC) has been harnessed to detect a wide range of chemical and biological stimuli. In most sensor designs, the information-rich response of the LC is transduced from an analyte-triggered change in the out-of-plane orientation of the LC. Quantifying the out-of-plane LC orientation, however, is often complicated by simultaneous changes in the in-plane orientation of the LC when using polarized light for transduction. Here we introduce a sensing approach that combines a dichroic dye-doped LC (DDLC) with unpolarized light and a photodiode to achieve precise quantification of analyte-driven changes in the out-of-plane orientations of LCs. We benchmark the performance of the new methodology against polarizer-based approaches using a model amphiphilic analyte in aqueous solution and show that the DDLC provides a substantial reduction in the coefficient of variation (300% to less than 5%), an enhanced analytical sensitivity (0.16 to 3.73 μM–1), and an expanded dynamic range. In addition, when used to sense concentration gradients of analytes, the new approach distinguishes differences as small as 0.03 μM/μm over a dynamic range of 2 μM/μm, significantly outperforming conventional polarizer-based approaches that detect differences of 0.3 μM/μm over a dynamic range of 0.6 μM/μm. Overall, we conclude that the improved sensing performance and simpler implementation (no polarizers) of the DDLC approach, as compared to conventional LC sensors based on crossed-polars, will facilitate the deployment of LC sensors in diverse contexts, including the development of high-throughput screens for chemical formulations.
{"title":"Polarizer-Free Dye-Doped Liquid Crystal Sensors with High Precision","authors":"Soumita Maiti, Milad Taghavi, Parag Chaudhari, Sangchul Roh, Itai Cohen, Alyssa B. Apsel, Nicholas L. Abbott","doi":"10.1021/acssensors.4c02913","DOIUrl":"https://doi.org/10.1021/acssensors.4c02913","url":null,"abstract":"The surface-induced ordering of liquid crystals (LC) has been harnessed to detect a wide range of chemical and biological stimuli. In most sensor designs, the information-rich response of the LC is transduced from an analyte-triggered change in the out-of-plane orientation of the LC. Quantifying the out-of-plane LC orientation, however, is often complicated by simultaneous changes in the in-plane orientation of the LC when using polarized light for transduction. Here we introduce a sensing approach that combines a dichroic dye-doped LC (DDLC) with unpolarized light and a photodiode to achieve precise quantification of analyte-driven changes in the out-of-plane orientations of LCs. We benchmark the performance of the new methodology against polarizer-based approaches using a model amphiphilic analyte in aqueous solution and show that the DDLC provides a substantial reduction in the coefficient of variation (300% to less than 5%), an enhanced analytical sensitivity (0.16 to 3.73 μM<sup>–1</sup>), and an expanded dynamic range. In addition, when used to sense concentration gradients of analytes, the new approach distinguishes differences as small as 0.03 μM/μm over a dynamic range of 2 μM/μm, significantly outperforming conventional polarizer-based approaches that detect differences of 0.3 μM/μm over a dynamic range of 0.6 μM/μm. Overall, we conclude that the improved sensing performance and simpler implementation (no polarizers) of the DDLC approach, as compared to conventional LC sensors based on crossed-polars, will facilitate the deployment of LC sensors in diverse contexts, including the development of high-throughput screens for chemical formulations.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"3 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582530","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 : 2025-03-09DOI: 10.1021/acssensors.4c02733
Hikaru Suzuki, Guodong Tong, Pabitra Nath, Yuki Hiruta, Daniel Citterio
In clinical diagnosis, the determination of target proteins at low concentration levels is generally performed by immunoassays, such as the enzyme-linked immunosorbent assay (ELISA), which is a time-consuming process. To date, paper-based ELISA platforms enabling faster and less expensive analysis have been developed, but their important issue for clinical applications is the limited sensitivity compared to conventional ELISA. To address this challenge, this paper introduces a simple, rapid, and highly sensitive detection method for non-nucleic acid targets achieved by integrating the CRISPR/Cas12a system into paper-based ELISA. An origami-type paper-based device enabling simple assay operation has been designed, and the detection of targets on the paper substrates is based on observing the fluorescence signal induced by the CRISPR/Cas12a enzyme cleaving a probe single-stranded DNA (ssDNA) labeled with fluorophore and quencher (FQ reporter). To enhance sensitivity, antibodies labeled with a network of multiple DNA activating the CRISPR/Cas12a enzyme have been utilized as detection antibodies. As a result, the developed device successfully boosted the detection sensitivity for both human IgG and the hepatitis B virus surface antigen (HBsAg). In particular, the limit of detection (LOD) for HBsAg was estimated to be 12 pg/mL, representing over 10-fold higher sensitivity compared with commercially available HBsAg ELISA kits (LOD: 200 pg/mL). In addition, the fluorescence response toward porcine whole blood samples containing different HBsAg concentrations was also confirmed by capturing images with a smartphone, followed by quantitative data analysis. These results demonstrate the potential applicability of the proposed platform for clinical tests at the point of care.
{"title":"Origami Paper-Based Immunoassay Device with CRISPR/Cas12a Signal Amplification","authors":"Hikaru Suzuki, Guodong Tong, Pabitra Nath, Yuki Hiruta, Daniel Citterio","doi":"10.1021/acssensors.4c02733","DOIUrl":"https://doi.org/10.1021/acssensors.4c02733","url":null,"abstract":"In clinical diagnosis, the determination of target proteins at low concentration levels is generally performed by immunoassays, such as the enzyme-linked immunosorbent assay (ELISA), which is a time-consuming process. To date, paper-based ELISA platforms enabling faster and less expensive analysis have been developed, but their important issue for clinical applications is the limited sensitivity compared to conventional ELISA. To address this challenge, this paper introduces a simple, rapid, and highly sensitive detection method for non-nucleic acid targets achieved by integrating the CRISPR/Cas12a system into paper-based ELISA. An origami-type paper-based device enabling simple assay operation has been designed, and the detection of targets on the paper substrates is based on observing the fluorescence signal induced by the CRISPR/Cas12a enzyme cleaving a probe single-stranded DNA (ssDNA) labeled with fluorophore and quencher (FQ reporter). To enhance sensitivity, antibodies labeled with a network of multiple DNA activating the CRISPR/Cas12a enzyme have been utilized as detection antibodies. As a result, the developed device successfully boosted the detection sensitivity for both human IgG and the hepatitis B virus surface antigen (HBsAg). In particular, the limit of detection (LOD) for HBsAg was estimated to be 12 pg/mL, representing over 10-fold higher sensitivity compared with commercially available HBsAg ELISA kits (LOD: 200 pg/mL). In addition, the fluorescence response toward porcine whole blood samples containing different HBsAg concentrations was also confirmed by capturing images with a smartphone, followed by quantitative data analysis. These results demonstrate the potential applicability of the proposed platform for clinical tests at the point of care.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"8 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582521","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 : 2025-03-09DOI: 10.1021/acssensors.4c0291310.1021/acssensors.4c02913
Soumita Maiti, Milad Taghavi, Parag Chaudhari, Sangchul Roh, Itai Cohen, Alyssa B. Apsel and Nicholas L. Abbott*,
The surface-induced ordering of liquid crystals (LC) has been harnessed to detect a wide range of chemical and biological stimuli. In most sensor designs, the information-rich response of the LC is transduced from an analyte-triggered change in the out-of-plane orientation of the LC. Quantifying the out-of-plane LC orientation, however, is often complicated by simultaneous changes in the in-plane orientation of the LC when using polarized light for transduction. Here we introduce a sensing approach that combines a dichroic dye-doped LC (DDLC) with unpolarized light and a photodiode to achieve precise quantification of analyte-driven changes in the out-of-plane orientations of LCs. We benchmark the performance of the new methodology against polarizer-based approaches using a model amphiphilic analyte in aqueous solution and show that the DDLC provides a substantial reduction in the coefficient of variation (300% to less than 5%), an enhanced analytical sensitivity (0.16 to 3.73 μM–1), and an expanded dynamic range. In addition, when used to sense concentration gradients of analytes, the new approach distinguishes differences as small as 0.03 μM/μm over a dynamic range of 2 μM/μm, significantly outperforming conventional polarizer-based approaches that detect differences of 0.3 μM/μm over a dynamic range of 0.6 μM/μm. Overall, we conclude that the improved sensing performance and simpler implementation (no polarizers) of the DDLC approach, as compared to conventional LC sensors based on crossed-polars, will facilitate the deployment of LC sensors in diverse contexts, including the development of high-throughput screens for chemical formulations.
{"title":"Polarizer-Free Dye-Doped Liquid Crystal Sensors with High Precision","authors":"Soumita Maiti, Milad Taghavi, Parag Chaudhari, Sangchul Roh, Itai Cohen, Alyssa B. Apsel and Nicholas L. Abbott*, ","doi":"10.1021/acssensors.4c0291310.1021/acssensors.4c02913","DOIUrl":"https://doi.org/10.1021/acssensors.4c02913https://doi.org/10.1021/acssensors.4c02913","url":null,"abstract":"<p >The surface-induced ordering of liquid crystals (LC) has been harnessed to detect a wide range of chemical and biological stimuli. In most sensor designs, the information-rich response of the LC is transduced from an analyte-triggered change in the out-of-plane orientation of the LC. Quantifying the out-of-plane LC orientation, however, is often complicated by simultaneous changes in the in-plane orientation of the LC when using polarized light for transduction. Here we introduce a sensing approach that combines a dichroic dye-doped LC (DDLC) with unpolarized light and a photodiode to achieve precise quantification of analyte-driven changes in the out-of-plane orientations of LCs. We benchmark the performance of the new methodology against polarizer-based approaches using a model amphiphilic analyte in aqueous solution and show that the DDLC provides a substantial reduction in the coefficient of variation (300% to less than 5%), an enhanced analytical sensitivity (0.16 to 3.73 μM<sup>–1</sup>), and an expanded dynamic range. In addition, when used to sense concentration gradients of analytes, the new approach distinguishes differences as small as 0.03 μM/μm over a dynamic range of 2 μM/μm, significantly outperforming conventional polarizer-based approaches that detect differences of 0.3 μM/μm over a dynamic range of 0.6 μM/μm. Overall, we conclude that the improved sensing performance and simpler implementation (no polarizers) of the DDLC approach, as compared to conventional LC sensors based on crossed-polars, will facilitate the deployment of LC sensors in diverse contexts, including the development of high-throughput screens for chemical formulations.</p>","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"10 3","pages":"1870–1879 1870–1879"},"PeriodicalIF":8.2,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713847","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 : 2025-03-09DOI: 10.1021/acssensors.4c0273310.1021/acssensors.4c02733
Hikaru Suzuki, Guodong Tong, Pabitra Nath, Yuki Hiruta and Daniel Citterio*,
In clinical diagnosis, the determination of target proteins at low concentration levels is generally performed by immunoassays, such as the enzyme-linked immunosorbent assay (ELISA), which is a time-consuming process. To date, paper-based ELISA platforms enabling faster and less expensive analysis have been developed, but their important issue for clinical applications is the limited sensitivity compared to conventional ELISA. To address this challenge, this paper introduces a simple, rapid, and highly sensitive detection method for non-nucleic acid targets achieved by integrating the CRISPR/Cas12a system into paper-based ELISA. An origami-type paper-based device enabling simple assay operation has been designed, and the detection of targets on the paper substrates is based on observing the fluorescence signal induced by the CRISPR/Cas12a enzyme cleaving a probe single-stranded DNA (ssDNA) labeled with fluorophore and quencher (FQ reporter). To enhance sensitivity, antibodies labeled with a network of multiple DNA activating the CRISPR/Cas12a enzyme have been utilized as detection antibodies. As a result, the developed device successfully boosted the detection sensitivity for both human IgG and the hepatitis B virus surface antigen (HBsAg). In particular, the limit of detection (LOD) for HBsAg was estimated to be 12 pg/mL, representing over 10-fold higher sensitivity compared with commercially available HBsAg ELISA kits (LOD: 200 pg/mL). In addition, the fluorescence response toward porcine whole blood samples containing different HBsAg concentrations was also confirmed by capturing images with a smartphone, followed by quantitative data analysis. These results demonstrate the potential applicability of the proposed platform for clinical tests at the point of care.
{"title":"Origami Paper-Based Immunoassay Device with CRISPR/Cas12a Signal Amplification","authors":"Hikaru Suzuki, Guodong Tong, Pabitra Nath, Yuki Hiruta and Daniel Citterio*, ","doi":"10.1021/acssensors.4c0273310.1021/acssensors.4c02733","DOIUrl":"https://doi.org/10.1021/acssensors.4c02733https://doi.org/10.1021/acssensors.4c02733","url":null,"abstract":"<p >In clinical diagnosis, the determination of target proteins at low concentration levels is generally performed by immunoassays, such as the enzyme-linked immunosorbent assay (ELISA), which is a time-consuming process. To date, paper-based ELISA platforms enabling faster and less expensive analysis have been developed, but their important issue for clinical applications is the limited sensitivity compared to conventional ELISA. To address this challenge, this paper introduces a simple, rapid, and highly sensitive detection method for non-nucleic acid targets achieved by integrating the CRISPR/Cas12a system into paper-based ELISA. An origami-type paper-based device enabling simple assay operation has been designed, and the detection of targets on the paper substrates is based on observing the fluorescence signal induced by the CRISPR/Cas12a enzyme cleaving a probe single-stranded DNA (ssDNA) labeled with fluorophore and quencher (FQ reporter). To enhance sensitivity, antibodies labeled with a network of multiple DNA activating the CRISPR/Cas12a enzyme have been utilized as detection antibodies. As a result, the developed device successfully boosted the detection sensitivity for both human IgG and the hepatitis B virus surface antigen (HBsAg). In particular, the limit of detection (LOD) for HBsAg was estimated to be 12 pg/mL, representing over 10-fold higher sensitivity compared with commercially available HBsAg ELISA kits (LOD: 200 pg/mL). In addition, the fluorescence response toward porcine whole blood samples containing different HBsAg concentrations was also confirmed by capturing images with a smartphone, followed by quantitative data analysis. These results demonstrate the potential applicability of the proposed platform for clinical tests at the point of care.</p>","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"10 3","pages":"1811–1821 1811–1821"},"PeriodicalIF":8.2,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713846","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}
Understanding dynamic changes within cellular microenvironments is crucial for elucidating biological processes and developing targeted therapies. Here, we present a rapid and straightforward strategy for profiling tumor microenvironments via fluorogenic crystallization driven by enzyme-instructed excited-state intramolecular proton transfer (ESIPT). By engineering ESIPT-based fluorophores, we achieve selective crystallization with strong dual-emission ratiometric fluorescence signals that are easily visualized, offering a real-time readout of tumor microenvironmental variations. We demonstrate that this method enables the efficient detection of tumor microenvironmental features, including enzymatic activity and pH heterogeneity, across different cellular models. This approach provides a simple, efficient, and versatile tool for studying microenvironment dynamics with broad potential applications in disease diagnosis, drug discovery, and personalized medicine.
{"title":"Fluorogenic Crystallization via Enzyme-Instructed Excited-State Intramolecular Proton Transfer for Dynamic Microenvironment Profiling","authors":"Yanglin Jiang, Qizheng Zhang, Xunwu Hu, Ting Liang, Ailin Sun, Chenjie Xu, Peng Wang, Ye Zhang","doi":"10.1021/acssensors.4c03641","DOIUrl":"https://doi.org/10.1021/acssensors.4c03641","url":null,"abstract":"Understanding dynamic changes within cellular microenvironments is crucial for elucidating biological processes and developing targeted therapies. Here, we present a rapid and straightforward strategy for profiling tumor microenvironments via fluorogenic crystallization driven by enzyme-instructed excited-state intramolecular proton transfer (ESIPT). By engineering ESIPT-based fluorophores, we achieve selective crystallization with strong dual-emission ratiometric fluorescence signals that are easily visualized, offering a real-time readout of tumor microenvironmental variations. We demonstrate that this method enables the efficient detection of tumor microenvironmental features, including enzymatic activity and pH heterogeneity, across different cellular models. This approach provides a simple, efficient, and versatile tool for studying microenvironment dynamics with broad potential applications in disease diagnosis, drug discovery, and personalized medicine.","PeriodicalId":24,"journal":{"name":"ACS Sensors","volume":"46 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570256","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}