A new fluorescent probe with high selectivity and sensitivity for Cys detection in bovine serum

Cysteine (Cys) is one of the most basic mercaptans in the human body. As an important endogenous small molecule mercaptan, Cys plays a vital role in various physiological processes and can participate in maintaining redox balance to ensure homeostasis. Abnormal Cys levels can lead to a variety of diseases. However, the detection of cysteine may be interfered with by other small molecule biothiols. Therefore, the design of fluorescent probes based on the structural characteristics and reactivity of cysteine has become the focus of current research. In this paper, a fluorescent probe (3-(2H-benzo[d][1,2,3]triazol-2-yl)-2-oxo-2H-benzo[g]chromen-8-yl acrylate, BTAB) for Cys detection was synthesized with acrylic ester as the reaction site. Under the conditions of gradual optimization, BTAB can achieve selectivity and anti-interference ability for Cys detection. The linear range of Cys was 0.3-10 μM, and the detection limit was 0.154 μM. Finally, this probe was applied to detect the Cys content in bovine serum samples with satisfactory results.