Flexible sensors are attractive due to potential applications in body exercise and ambient gas monitoring systems.Cellulose and its derivatives have combined superiorities such as intrinsic and structural flexibility,...Flexible sensors are attractive due to potential applications in body exercise and ambient gas monitoring systems.Cellulose and its derivatives have combined superiorities such as intrinsic and structural flexibility,ease of chemical functionalization,moisture sensitivity,and mechanical stability,enabling them to be promising candidates as flexible supporting substrates and flexible sensitive materials.Significant progress consequently has been achieved to improve mechanical,electrical,and chemical performance.The latest advance in materials synthesis,structure design,fabrication control,and working mechanism of novel cellulose-based flexible sensors are reviewed and discussed,including strain sensors,humidity sensors,and harmful gas sensors.Various strategies were summarized to enhance sensor performance by surface group modifications,inorganic and organic conducting fillers optimization,multilayer structure design.Newly emerged processing techniques of self-assembly,vacuum filtration,and 3D printing were introduced as well to construct multiscale microstructures.The integration of multiple sensors toward smart and healthy exercise monitoring system is briefly reviewed.The facing challenges and future opportunities of cellulose-based flexible sensors were discussed and proposed at the end.This review provides inspiration and guidelines on how to design and fabricate cellulose-based flexible sensors.展开更多
Cellulose nanocrystals(CNCs), a unique and promising natural material extracted from native cellulose, have attracted considerable attention owing to their physical properties and special surface chemistry. This revie...Cellulose nanocrystals(CNCs), a unique and promising natural material extracted from native cellulose, have attracted considerable attention owing to their physical properties and special surface chemistry. This review focuses on chemical conjugation strategies that can be used for preparation of fluorescent-molecule labeled CNCs and the development of biomaterials.Furthermore, their application in the detection of metal ions and future development prospects are discussed. We hope to provide a clear view of the strategies for surface fluorescent modification of CNCs and their application in detection of metal ions.展开更多
Au/cellulose-PEPC/Au surface-type humidity sensors were fabricated by drop-casting cellulose and poly-N-epoxypropylcarbazole （PEPC） blend thin films. A blend of 2wt% of each cellulose and PEPC in benzol was used for...Au/cellulose-PEPC/Au surface-type humidity sensors were fabricated by drop-casting cellulose and poly-N-epoxypropylcarbazole （PEPC） blend thin films. A blend of 2wt% of each cellulose and PEPC in benzol was used for the deposition of humidity sensing films. Blend films were deposited on glass substrates with preliminary deposited surface-type gold electrodes. Films of different thicknesses of cellulose and PEPC composite were deposited by drop-casting technique. A change in electrical resistance and capacitance of the fabricated devices was observed by increasing the relative humidity in the range of 0-95% RH. It was observed that the capacitances of the sensors increase, while their resistances decrease with increasing the relative humidity. The sensors were connected to op-amp square wave oscillators. It was observed that with increasing the relative humidity, the oscillator＇s frequencies were also increased in the range of 4.2-12.0 kHz for 65μm thick film sample, 4.1-9.0 kHz for 88μm thick film sample, and 4.2-9.0 kHz for 210μm sample. Effects of film thickness on the oscillator＇s frequency with respect to humidity were also investigated. This polymer humidity sensor controlled oscillator can be used for short-range and long-range remote systems at environmental monitoring and assessment of the humidity level.展开更多
Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode m...Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode modified with one-dimensional Cu(OH)_(2)/carboxymethyl cellulose(CMC)composite nanofibers was fabricated and investigated for the detection of aspirin.Scanning electron microscopy was employed to examine the morphological characteristics of these composite nanofibers.Cyclic voltammetry and electrochemical impedance spectroscopy were used to assess the electrochemical performance of a Cu(OH)_(2)/CMC composite nanofiber-modified electrode.The findings indicate that the modified electrode has a very high sensitivity to aspirin.The observed enhanced performance could be a result of the high surface-to-volume ratio of the composite nanofibers and their superior electron-transport characteristics,which may hasten electron transfer between aspirin and the surfaces of the modified electrode.This detection technique also demonstrated strong selectivity for aspirin.These findings imply that the technique can be applied as a highly effective and selective approach to aspirin measurement in biological science.展开更多
The development of implantable bioelectronics is driven by emerging applications including continuous health monitoring and human-machine interfacing.The mechanical mismatch between implanted bioelectronics and tissue...The development of implantable bioelectronics is driven by emerging applications including continuous health monitoring and human-machine interfacing.The mechanical mismatch between implanted bioelectronics and tissues not only compromises device accuracy,but also causes interference with tissues undesirably.To address this issue,it is necessary to develop ultrasoft and biocompatible fiber strain sensor with proper stretchability and sensitivity.Here,we fabricate a bacterial cellulose-based sensing fiber which possesses the stretchability and elastic modulus(~102 kPa)close to those of soft tissues.In addition,such fiber has high sensitivity to tiny tensile force/strain(8.8×10^(−3)N/2.5%)and low cell cytotoxicity.These excellent properties make the bacterial cellulose(BC)-based sensing fiber an excellent candidate of implantable bioelectric devices for monitoring subtle motions of organs.We demonstrate this by applying it for continuous monitoring of human pulse and bullfrog heartbeats.The(BC/oxBC)@PANI(ox=oxidized and PANI=polyaniline)fibers can further be woven into an array sensor and serve more complex sensing functions,such as multipoint force perception and shape recognition as demonstrated.展开更多
As the most abundant natural polymer material on the earth,cellulose is a promising sustainable sensing material due to its high mechanical strength,excellent biocompatibility,good degrada-tion,and regeneration abilit...As the most abundant natural polymer material on the earth,cellulose is a promising sustainable sensing material due to its high mechanical strength,excellent biocompatibility,good degrada-tion,and regeneration ability.Considering the inherent advantages of cellulose and the success of modern sensors,applying cellulose to sensors has always been the subject of considerable investigation,and significant progress has been made in recent decades.Herein,we reviewed the research progress of cellulose functional materials(CFMs)in recent years.According to the different sources of cellulose,the classification and preparation methods for the design and func-tionalization of cellulose were summarized with the emphasis on the relationship between their structure and properties.Besides,the applications of advanced sensors based on CFMs in recent years were also discussed.Finally,the potential challenges and prospects of the development of sensor based on CFMs were outlined.展开更多
With increasing emphasis on green chemistry,biomass-based materials have attracted increased attention regarding the development of highly efficient functional materials.Herein,a new pore-rich cellulose nanofibril aer...With increasing emphasis on green chemistry,biomass-based materials have attracted increased attention regarding the development of highly efficient functional materials.Herein,a new pore-rich cellulose nanofibril aerogel is utilized as a substrate to integrate highly conductive polypyrrole and active nanoflower-like nickel-cobalt layered double hydroxide through in situ chemical polymerization and electrodeposition.This ternary composite can act as an effective self-supported electrode for the electrocatalytic oxidation of glucose.With the synergistic effect of three heterogeneous components,the electrode achieves outstanding glucose sensing performance,including a high sensitivity(851.4μA·mmol^(−1)·L·cm^(−2)),a short response time(2.2 s),a wide linear range(two stages:0.001−8.145 and 8.145−35.500 mmol·L^(−1)),strong immunity to interference,outstanding intraelectrode and interelectrode reproducibility,a favorable toxicity resistance(Cl^(‒)),and a good long-term stability(maintaining 86.0%of the original value after 30 d).These data are superior to those of some traditional glucose sensors using nonbiomass substrates.When determining the blood glucose level of a human serum,this electrode realizes a high recovery rate of 97.07%–98.89%,validating the potential for highperformance blood glucose sensing.展开更多
Photoluminescent hybrid materials containing carboxymethyl cellulose and lanthanide ions（Eu3＋, Tb3＋）were prepared by a facile method under ambient conditions. Lanthanide ions were covalently grafted to the cellulo...Photoluminescent hybrid materials containing carboxymethyl cellulose and lanthanide ions（Eu3＋, Tb3＋）were prepared by a facile method under ambient conditions. Lanthanide ions were covalently grafted to the cellulose framework through coordination with the carboxylic groups of the cellulose. Hybrid materials were fabricated as hydrogel and aerogel. As shown by SEM and pore parameters, aerogel materials which were obtained by supercritical CO2 drying show hierarchical porous structure. The photoluminescence spectrum of the hybrid materials shows the characteristic red emission of Eu3＋ ion and green emission of Tb3＋. Further luminescent investigations reveal that these hybrid materials can detect Fe3＋ with relative selectivity and high sensitivity, which suggests that the hybrid materials could be a promising luminescent probe for selectively sensing Fe3＋ ion.展开更多
基金the NSFC Funds under Grant 52075440National Key Research and Development Program of China(No.2021YFD1600402)+2 种基金Central Guidance on Local Science and Technology Development Fund of Shaanxi Province(No.2020-ZYYD-NCC-9)Shaanxi Provincial Department of Education Collaborative Innovation Center Project(20JY052)National Natural Science Foundation of China(No.52072075)。
文摘Flexible sensors are attractive due to potential applications in body exercise and ambient gas monitoring systems.Cellulose and its derivatives have combined superiorities such as intrinsic and structural flexibility,ease of chemical functionalization,moisture sensitivity,and mechanical stability,enabling them to be promising candidates as flexible supporting substrates and flexible sensitive materials.Significant progress consequently has been achieved to improve mechanical,electrical,and chemical performance.The latest advance in materials synthesis,structure design,fabrication control,and working mechanism of novel cellulose-based flexible sensors are reviewed and discussed,including strain sensors,humidity sensors,and harmful gas sensors.Various strategies were summarized to enhance sensor performance by surface group modifications,inorganic and organic conducting fillers optimization,multilayer structure design.Newly emerged processing techniques of self-assembly,vacuum filtration,and 3D printing were introduced as well to construct multiscale microstructures.The integration of multiple sensors toward smart and healthy exercise monitoring system is briefly reviewed.The facing challenges and future opportunities of cellulose-based flexible sensors were discussed and proposed at the end.This review provides inspiration and guidelines on how to design and fabricate cellulose-based flexible sensors.
基金the National Natural Science Foundation of China (51373131)Fundamental Research Funds for the Central Universities (XDJK2016A017 and XDJK2016C033 )+1 种基金Project of Basic Science and Advanced Technology Research, Chongqing Science and Technology Commission (cstc2016, jcyjA0796)the Talent Project of Southwest University (SWU115034)
文摘Cellulose nanocrystals(CNCs), a unique and promising natural material extracted from native cellulose, have attracted considerable attention owing to their physical properties and special surface chemistry. This review focuses on chemical conjugation strategies that can be used for preparation of fluorescent-molecule labeled CNCs and the development of biomaterials.Furthermore, their application in the detection of metal ions and future development prospects are discussed. We hope to provide a clear view of the strategies for surface fluorescent modification of CNCs and their application in detection of metal ions.
基金GIK Institute of Engineering Sciences and Technology for the support extended to this work
文摘Au/cellulose-PEPC/Au surface-type humidity sensors were fabricated by drop-casting cellulose and poly-N-epoxypropylcarbazole （PEPC） blend thin films. A blend of 2wt% of each cellulose and PEPC in benzol was used for the deposition of humidity sensing films. Blend films were deposited on glass substrates with preliminary deposited surface-type gold electrodes. Films of different thicknesses of cellulose and PEPC composite were deposited by drop-casting technique. A change in electrical resistance and capacitance of the fabricated devices was observed by increasing the relative humidity in the range of 0-95% RH. It was observed that the capacitances of the sensors increase, while their resistances decrease with increasing the relative humidity. The sensors were connected to op-amp square wave oscillators. It was observed that with increasing the relative humidity, the oscillator＇s frequencies were also increased in the range of 4.2-12.0 kHz for 65μm thick film sample, 4.1-9.0 kHz for 88μm thick film sample, and 4.2-9.0 kHz for 210μm sample. Effects of film thickness on the oscillator＇s frequency with respect to humidity were also investigated. This polymer humidity sensor controlled oscillator can be used for short-range and long-range remote systems at environmental monitoring and assessment of the humidity level.
基金The authors wish to acknowledge financial support from the Science and Technology Projects in Jilin Province Department of Education(Grant No.JJKH20220239KJ).
文摘Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode modified with one-dimensional Cu(OH)_(2)/carboxymethyl cellulose(CMC)composite nanofibers was fabricated and investigated for the detection of aspirin.Scanning electron microscopy was employed to examine the morphological characteristics of these composite nanofibers.Cyclic voltammetry and electrochemical impedance spectroscopy were used to assess the electrochemical performance of a Cu(OH)_(2)/CMC composite nanofiber-modified electrode.The findings indicate that the modified electrode has a very high sensitivity to aspirin.The observed enhanced performance could be a result of the high surface-to-volume ratio of the composite nanofibers and their superior electron-transport characteristics,which may hasten electron transfer between aspirin and the surfaces of the modified electrode.This detection technique also demonstrated strong selectivity for aspirin.These findings imply that the technique can be applied as a highly effective and selective approach to aspirin measurement in biological science.
基金supported by the National Natural Science Foundation of China(Nos.52172283 and 22078197)Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515012506,2020A1515110480,2022A1515011815,and 2019A1515111156).
文摘The development of implantable bioelectronics is driven by emerging applications including continuous health monitoring and human-machine interfacing.The mechanical mismatch between implanted bioelectronics and tissues not only compromises device accuracy,but also causes interference with tissues undesirably.To address this issue,it is necessary to develop ultrasoft and biocompatible fiber strain sensor with proper stretchability and sensitivity.Here,we fabricate a bacterial cellulose-based sensing fiber which possesses the stretchability and elastic modulus(~102 kPa)close to those of soft tissues.In addition,such fiber has high sensitivity to tiny tensile force/strain(8.8×10^(−3)N/2.5%)and low cell cytotoxicity.These excellent properties make the bacterial cellulose(BC)-based sensing fiber an excellent candidate of implantable bioelectric devices for monitoring subtle motions of organs.We demonstrate this by applying it for continuous monitoring of human pulse and bullfrog heartbeats.The(BC/oxBC)@PANI(ox=oxidized and PANI=polyaniline)fibers can further be woven into an array sensor and serve more complex sensing functions,such as multipoint force perception and shape recognition as demonstrated.
基金supported by Young Elite Scientists Sponsorship Program by CAST(No.2019QNRC001)Fundamental Research Funds for the Central Universities(No.2572021CG05)+5 种基金China Postdoctoral Science Foundation Funded Project(No.2022T150102,No.2021M700735,No.2019T120249,No.2018M630331)Heilongjiang Postdoctoral Fund(No.LBH-Z18010,No.LBH-TZ1001)National Natural Science Foundation of China(No.51903031,No.31770619,No.62205052,No.32271805)State Key Program of National Natural Science Foundation of China(No.31930076)the 111 Project(No.B20088)Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team).
文摘As the most abundant natural polymer material on the earth,cellulose is a promising sustainable sensing material due to its high mechanical strength,excellent biocompatibility,good degrada-tion,and regeneration ability.Considering the inherent advantages of cellulose and the success of modern sensors,applying cellulose to sensors has always been the subject of considerable investigation,and significant progress has been made in recent decades.Herein,we reviewed the research progress of cellulose functional materials(CFMs)in recent years.According to the different sources of cellulose,the classification and preparation methods for the design and func-tionalization of cellulose were summarized with the emphasis on the relationship between their structure and properties.Besides,the applications of advanced sensors based on CFMs in recent years were also discussed.Finally,the potential challenges and prospects of the development of sensor based on CFMs were outlined.
基金supported by the National Natural Science Foundation of China(Grant No.31901249),the Hunan Provincial Natural Science Foundation of China(Grant No.2022JJ30079)the Hunan Provincial Technical Innovation Platform and Talent Program in Science and Technology(Grant No.2020RC3041)the Training Program for Excellent Young Innovators of Changsha(Grant No.kq2106056).
文摘With increasing emphasis on green chemistry,biomass-based materials have attracted increased attention regarding the development of highly efficient functional materials.Herein,a new pore-rich cellulose nanofibril aerogel is utilized as a substrate to integrate highly conductive polypyrrole and active nanoflower-like nickel-cobalt layered double hydroxide through in situ chemical polymerization and electrodeposition.This ternary composite can act as an effective self-supported electrode for the electrocatalytic oxidation of glucose.With the synergistic effect of three heterogeneous components,the electrode achieves outstanding glucose sensing performance,including a high sensitivity(851.4μA·mmol^(−1)·L·cm^(−2)),a short response time(2.2 s),a wide linear range(two stages:0.001−8.145 and 8.145−35.500 mmol·L^(−1)),strong immunity to interference,outstanding intraelectrode and interelectrode reproducibility,a favorable toxicity resistance(Cl^(‒)),and a good long-term stability(maintaining 86.0%of the original value after 30 d).These data are superior to those of some traditional glucose sensors using nonbiomass substrates.When determining the blood glucose level of a human serum,this electrode realizes a high recovery rate of 97.07%–98.89%,validating the potential for highperformance blood glucose sensing.
基金Project supported by the National Natural Science Foundation of China(21161023,21661034)
文摘Photoluminescent hybrid materials containing carboxymethyl cellulose and lanthanide ions（Eu3＋, Tb3＋）were prepared by a facile method under ambient conditions. Lanthanide ions were covalently grafted to the cellulose framework through coordination with the carboxylic groups of the cellulose. Hybrid materials were fabricated as hydrogel and aerogel. As shown by SEM and pore parameters, aerogel materials which were obtained by supercritical CO2 drying show hierarchical porous structure. The photoluminescence spectrum of the hybrid materials shows the characteristic red emission of Eu3＋ ion and green emission of Tb3＋. Further luminescent investigations reveal that these hybrid materials can detect Fe3＋ with relative selectivity and high sensitivity, which suggests that the hybrid materials could be a promising luminescent probe for selectively sensing Fe3＋ ion.
