A New Colorimetric Sensor for Cysteine Determination Based on Dual Reacting‐mediated Strategy

Abstract

Rapid and simple determination of cysteine is a key requirement for both diagnosis and treatment of diseases. A novel concept is proposed for combining dual reacting‐mediated process into the construction of a simple yet effective colorimetric strategy for cysteine detecting, which is based on the analyte‐induced formation of ferrous ion and graphene oxide‐supported ionic recognition through selective coordination process between phenanthroline molecule and ferrous ion. In colorimetric analysis, the simple principle of ferrous ion that cysteine‐induced can be recognized by phenanthroline indicator due to their good binding affinity and therefore provided a sensitive optical readout for conveniently detecting cysteine. Proof‐concept experiments demonstrate that the proposed colorimetric system shows rapid response toward cysteine determination as well as with a satisfying detection limit of 4.8 μM only by using simple UV–Vis spectroscopy and 15 μM with the naked eye.