Easy-to-Prepare Mini-Chemosensor Array for Simultaneous Detection of Cysteine and Glutathione Derivatives

We herein propose an easy-to-prepare mini-chemosensor array constructed by two-types of off-the-shelf coumarin dyes for simultaneous classification and quantification of sulfur-containing amino acids (SCAAs) (i.e., l-cysteine, l-cystine, l-homocysteine, glutathione, and glutathione disulfide). The detection mechanism of SCAAs relied on a coordination-based sensor array (CBSA) utilizing the competitive binding among the coumarin dye, a Zn²⁺ ion and SCAAs. The reversible feature of the coordination bond of the coumarin-Zn²⁺ resulted in UV/vis spectral shifts and fluorescence enhancement in response to the analytes, offering the multianalyte detection in high accuracy. Furthermore, a mixture of glutathione and l-cysteine was successfully quantified in a sample containing human blood serum. This study would be an important example of the optical chemosensor array toward the rapid and accurate detection of biomarkers.