Highly selective sequential detection of Cu2+ and S2− using a large stokes shift peptide-based fluorescent probe and its multi-application
Yi Ren, Mengying Jia, Shiyi Xiong, Chunmei Pu, Peng Wang, Yong An
Abstract
A novel peptidyl fluorescent probe DAH was synthesized by conjugating a dansyl fluorophore with dipeptide (Ala-His-NH 2 ) using Fmoc solid-phase peptide synthesis (SPPS) technology. DAH exhibited a highly selective fluorescence quenching response towards Cu 2+ , and the limit of detection (LOD) for Cu 2+ was 18.0 nM. In addition, the in situ complex DAH Cu 2+ was developed as a new relay probe for S 2− based on the reversible formation-separation method, and the LOD for S 2− down to 72.6 nM. It is worth noting that DAH not only has potential application prospects for detecting Cu 2+ and S 2− in real samples, but also was used for fluorescence imaging of Cu 2+ and S 2− in living cells and zebrafish larvae. Notably, DAH was made into portable test strips and used for the definite visual analysis of Cu 2+ and S 2− under UV light at 365 nm. Moreover, the DAH Cu 2+ complex monitored the H 2 S generated during the spoilage process of the two kinds of meat in real time through the naked eye. Additionally, the sensing application of DAH with Cu 2+ and S 2− was determined by the molecular logic gates. Interestingly, the developed portable smartphone App platform achieved the onsite quantitative analysis with satisfactory results.