Flexible Electrochemical Sensor Based On Surface Functional Carbonized Silk Fabrics

Due to the urgent needs in health monitoring,clinical and other aspects,more and more attention has been paid to the research of flexible sensors.Flexible electrochemical sensor can detect the concentration of biomarkers(such as glucose,lactic acid,etc.)in human tissue fluid(blood,sweat,etc.)quickly and in real time with high sensitivity and good stability,and have great application potential in wearable biosensors.Carbonized silk fabrics(CSF)with its natural flexibility,excellent electrical conductivity and good chemical stability,have been widely used in many fields,such as capacitors,lithium ion batteries sensors and so on.Due to its inherent self-supporting flexible characteristics,CSF can be used as a working electrode substrate of flexible electrochemical sensor to detect different biomaterials by modifying its surface.In this paper,ordered mesoporous carbon/carbonized silk fabrics(OMC/CSF)composite and polyaniline arrays/carbonized silk fabrics(PANI/CSF)composites were prepared by using CSF as the flexible substrate.The flexible enzyme-free biosensors for dopamine and pH with excellent performance were constructed.The specific research contents are:(1)The CSF was selected as the flexible substrate,the block polymer was used as the soft template,and the phenolic resol was used as the carbon source.A hydrothermal interface-induced self-assembly route was used to prepare the ordered mesostructure on the surface of the CSF.The composite material was carbonized by heat treatment to obtain ordered mesoporous carbon/ carbonized silk fabrics(OMC/CSF)composite.Characterization by FE-SEM,TEM,and XRD showed that the surface of the CSF was evenly covered with an OMC layer with the pore size of about 10 nm.The OMC/CSF composite was used as a flexible self-supporting working electrode,and the dopamine was detected by three-electrode electrochemical method.The results show that OMC/CSF has excellent catalytic performance for dopamine with the detection limit of only 0.11 ?M and a linear range of 0.2-80 ?M,which is mainly attributed to the synergistic effect of the high surface area of ordered mesoporous carbon and the high conductivity of carbonized silk fabrics.It provides a simple and effective approach for the preparation of flexible enzyme-free biosensors.(2)Polyaniline arrays were successfully grown on CSF via chemical oxidation by using aniline as the precursors.The polyaniline/carbonized silk fabrics(PANI/CSF)composite was used as self-supporting flexible pH sensor,which shows excellent linearity,rapid detection ability and good stability in the pH range of 3.0-11.0.