A Single-chain Templated Polymer-based Target Receptor as a New Platform for Label-free Selective Electrochemical Sensing.

We report a novel single-chain polymer-based chemical receptor that can be used for the label-free electrochemical detection of an analyte with high selectivity. The polymer was developed using poly-N-isopropylacrylamide (pNIPAM) as a backbone structure in addition to other functional monomers that are used to imprint the template molecule 4-nitrophenol. The polymer also contains a redox reporting monomers (ferrocene) which create a change in the electrochemical signal upon molecular recognition. We hypothesize that the analyte binding to the receptor causes the polymer conformation change from the extended to the collapsed phase. After anchoring the polymer-based receptors onto the surfaces of the gold electrode, when exposed to the analyte, the changes in the electrochemical signals were observed which confirmed the selective target binding as well as the polymer conformation change as a result.