Fluorescent sensor array for selective recognition of biothiols

Abstract

Biological thiols play essential roles in life activities. Detection and differentiation of different biothiols is of crucial need in biomedical research and diagnostics. Herein, a novel fluorescent sensor array was constructed to discriminate six kinds of biothiols including Cysteine (Cys), N-acetylcystein (NAC), 2-mercaptoethanol (MCE), Homocysteine (Hcy), Glutathione (GSH), and Glutathione disulfide (GSSG) simultaneously. This sensor array was fabricated by using three kinds of metal ions (i.e., Fe3+, Ni2+, and Cu2+)–N-CDs pairs. The N-CDs were synthesized with urea as nitrogen sources and folic acid as carbon sources via a simple microwave approach. Based on the competitive interactions of N-CDs with metal ions and thiols, the sensor array exhibits diverse fluorescence intensity response patterns, six thiols could be effectively and simultaneously differentiated in a wide concentration range (≧50 μM) by principal component analysis (PCA). Morover, double-blind samples of biothiols were recognized with 97.2% accuracy through linear discrimination analysis (LDA). More importantly, the sensor array showed good practicability in complex media such as fetal bovine serum, demonstrating this proposed sensor array held a great potential for the identification of biological thiols in real samples.