Elimination Reaction-Based Benzimidazole Probe for Cysteine Detection and Its Application in Serum Sample Analysis

Benzimidazole-based compound 2-( -tolyl)-1 -benzo[d]imidazole ( ) and its derivative probe have been synthesized for the highly selective detection and quantification of Cys in human serum. The photophysical properties of and compound were evaluated by UV-vis absorption and fluorescence spectroscopy. showed high selectivity and sensitivity for Cys among tested analytes, including amino acids, anions, and cations. selectively reacts with Cys and results in compound with fluorescence turn-on effect. did not show any interference from the components in the serum matrix for Cys detection in the human serum sample. detects Cys in serum samples with 2.3-5.4-fold better LOD than reported methods. The detection limit of 86 nM and 43 nM in HEPES buffer using UV-visible and fluorescence spectroscopy, respectively, makes an excellent chemosensor for Cys detection.