Conjugated Polyelectrolyte Based Colorimetric Array for the Discrimination of Primary Amino Acids

Abstract We report a colorimetric sensor based on the supramolecular complex between a conformation‐sensitive cationic polythiophene derivative, poly(3‐(4‐methyl‐3‐thienyloxy)propyltrimethylammonium) (PMTPA) and 2‐naphthalenesulfonate (NS). It could be applied to discern 19 primary amino acids by the wavelength of PMTPA/NS. The sensing performance and mechanism was investigated by spectroscopic studies such as absorption and emission spectra. This approach relies on the disassembly of PMTPA/NS aggregates induced by the amphiphilic isoindole derivatives of amino acids formed in situ. 100% confidence limits for this discrimination could be achieved by using linear discriminant analysis (LDA).