The Preparation Of Conducting Polymer Nanocomosites And Their Applications In Sensors

Over the past decades,electrochemical sensors have attracted considerable attentions,due to their high sensitivity,ease of miniaturization,cost effectiveness,quick response time and simple fabrication procedure and been widely used in such aspects as biological medicine,environmental analysis,biochemical analysis.However,inactivation of decoration materials and nonspecific adsorption of proteins makes it remains highly challenging to achieve a highly selective response in real biological samples.In this work,in order to solve these two problems,two kinds of electrochemical sensors with high sensitivity were prepared.(1)Firstly,a nanocomposite consisting of PEDOT doped with PAS was prepared through electropolymerization.The composite possesses a large specific surface area and a large number of active sites and shows high catalytic activity towards the oxidation of nitrite.Under optimized experimental conditions,anodic peak currents are linearly related to nitrite concentrations in the range from 0.3 ?M to 6.6 mM,and the detection limit is 98 nM(at an S/N ratio of 3).(2)Afterwards,a novel biomolecular-repellent electrochemical biosensor platform is fabricated with a hydrophilic material-independent poly-dopamine,Fe3+-mediated tannic acid(TA)deposition and the branched structure of four-armed polyethylene glycol(PEG).Experimental result shows that charge-transfer resistance(Rct)versus target concentration is constituted from a good linear correlation from 0.1 fM to 10 pM and is associated with a limit of detection as low as 0.05 fM(S/N=3).Advantageously,the sensors that mentioned above could be capable of quantifying tagert in complex biological fluids,indicating its great potential diagnostic applications in clinical analysis.