Fabricating And Studying Performance Of Organic Electrochemical Transistors To Detect Ascorbic Acid Sensor

Because of its low operating voltage, good biocompatibility, and can be used in aqueous solution, the electrochemical sensor has been widely concerned . But at the same time, there are still some problems of selectivity and sensitivity . In this paper,electrochemical transistorsensor which is used for detection of ascorbic acid was fabricated,by using PEDOT:PSS as the semiconductor layer, doping with dimethyl sulfoxide (DMSO). It illustrates that electrochemical transistor sensor which we prepared for ascorbic acid detectionhas higher sensitivity, lower detection limits,better selectivity and linearitythan electrochemical sensor. In the end,instead of ascrobic acid, the electrochemical transistor sensor was applied in detection of actual samples containing ascrobic acid, the experiment result reached the excepted effect. These results show that electrochemical transistor sensor has a good application prospect onfast and efficient sensing detector.The main work is as follows(1) The PEDOT:PSS conductive film doped with dimethyl sulfoxide (DMSO) was prepared by spin coating and the conductivity were calculated. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were used to study the microstructure of the films. Experimental results show:the addition of DMSO leads to the increase of the content of PEDOT on the surface of the films, and a certain phase separation occurs, but the aggregation structure of the PEDOT:PSS films does not change. The conductivity of DMSO doped PEDOT:PSS film was improved obviously. The best performance is PH 1000 doped with DMSO 5%, the conductivity is 457 S/cm, the maximum current of the transfer curve can reach up to 0.6 mA. Therefore, the 5% DMSO doped PH 1000 type PEDOT:PSS was chosen as the semiconductor layer to prepare the electrochemical transistor sensor(2) In order to improve the response current,graphene oxide and carbon nanotubes were modified on gold electrode by doping to detect ascorbic acid molecules, and the results were compared with electrochemical sensors. Experimental results show: The degree of the conductance on the surface of the electrode plays a decisive role in the detection of the ascorbic acid molecule.Therefore, the better response current modified carbon nanotube materials with better conductivity was observed, which was about 2 times that of the bare gold electrode. Compared the detection results of two kinds of sensors, the electrochemical transistor sensor has lower detection limit and sensitivity, which is 1 ?M(3) In order to improve the selectivity of electrochemical transistor sensor,the molecularly imprinted polymer membrane was fabricated by electropolymerizing on the surface of Au electrode, with ascorbic acid (AA) as template molecule and o-phenulenediamine (o-PD) as functional monomer. Organic electrochemical transistor (OECT) modified with molecularly imprinted polymer (MIP) exhibited high selectivity and sensitivity for detecting AA.Experimental results show:The most optimal response current ofthe MIP modified OECT sensor had good linear relationships with concentration of AA in the ranges of 100 nM-3 ?M and 10 ?M-100?M, with the detection limit 300 nM.The selectivity of Organic electrochemical transistoris extremely superio, can distinguish the AA from the distractors...