The Preparation Of Fiber Based Organic Electrochemical Transistors And Its Application In Biosensor

Nanofiber and graphene both have large specific surface area and excellent electrical properties,a conductive fiber that modified by them can not only have good conductivity but also obtain prefect flexibility and weaving performance of the ordinary fiber.This conductive fiber can be used to assemble the fiber-based organic eletrochemical transistors(FECTs)with improving electronic transmission capacity and sensitivity,which,on the other hand,providing a good foundation for the realization of portable and wearable sensing device.In this paper,EVOH nanofibers(NF)prepared by melt extrusion phase separation method were coated on the surface of PA6(85D)fibers,then the PPy/NF/ PA6 composite fiber was obtained by the in situ polymerization.A gel electrolyte was made by phosphoric acid,water and PVA,then using it to assemble a PPy/NF/PA6 fiber-based organic electrochemical transistors(FECTs)and apply the FECTs in dopamine sensor.The results showed that the adsorption amount of PPy on the surface increased significantly if the fiber was modified by NF,meanwhile,the microscopic morphology of the PPy was improved and it looked like line,the resistance of the fiber that compounded by NF could reduce by 6 times.FECTs have excellent output curve and the switch response time is 0.5s.The FECTs dopamine sensor could has a significant current response within 0.5s for 1nm to 1000 n M dopamine,meanwhile,the device detection of dopamine will not be affected by interference substances like amino acids and uric acid.The graphene oxide(GO)was prepared according to the modified Hummer method,then GO was reduced through gas phase by hydrazine hydrate before coated on the fiber,finally the PPy/r GO/PA6 conductive fibers were obtained by in situ polymerizatio.The gel electrolyte was made by PVA,lithium perchlorate etc.,then it was assembled into the PPy/r GO/PA6 fiber-based organic electrochemical transistors(FECTs).The PPy/r GO/PA6 fiber was produced by immersed in 5mg/m L glucose oxidase solution and Nafion(wt=1%)solution and acted as the gate electrode,PPy/r GO/PA6(133.3D)was acted as the source-drain electrode,then they were assembled into a glucose sensor.The results showed that the incorporation of r GO can induce the growth of a large amount of interconnected,smooth and linear polypyrrole nanowires,which diameter was about 200-300 nm.Compared with NF composite material,r GO composite material can obtained more linear polypyrrole nanowires with much better morphology and higher conductivity.FECTs had excellent characteristic curves and its switching ratio was up to 102 orders of magnitude.The concentrations that the FECTs glucose sensor could detect ranged from 1n M/L to 1m M/L,and it can emerge an significant and rapid response current within 0.5s and reach a relative balance within 5s,when dropping with different concentrations of glucose solution.The normalized current will increased with the increase of glucose concentrations,and the curves showed a linear correlation with a correlation coefficient of 0.9368.In addition,The FECTs glucose sensor had an significant specificity for glucose,and it did not show special reactions when adding other interfering substances such as AA and UA.