Rapid, sensitive and selective detection of arginine using a simple azo-based colorimetric and fluorescent chemosensor

Abstract In this work, a new thiazole-based colorimetric and fluorescent chemosensor (ThiCS) has been developed for arginine (Arg) detection. It has revealed high sensitivity and selectivity toward arginine over other amino acids in aqueous acetonitrile media. Among various amino acids, only the amino acid arginine exhibited a visual color change and a bathochromic shift in UV–vis spectra in a few seconds due to the charge transformation between azo group of sensor and guanidino group of Arg. Moreover, interaction of ThiCS with Arg cause a red-shift in fluorescence emission accompanied with the fluorescence enhancement at 545 nm and fluorescence quenching at 486 nm. Since ThiCS could provide a vivid and reasonable response in the presence of detected amino acid within the pH range of 5–9, we can claim that the chemosensor can be utilized in any physical and biological conditions. More importantly, the sensor ThiCS has a wide linear detection range, low detection limit, high selectivity, and rapid response time for the detection of arginine under the experimental conditions. Besides, Arg can be detected in human blood plasma through this method resulting satisfactory color and spectral changes, which demonstrates the potential of application of ThiCS in real analysis.