Cascade Detection of Pyridoxal 5′-Phosphate and Al3+ Ions Based on Dual-Functionalized Red-Emitting Copper Nanoclusters

Pyridoxal 5'-phosphate (PLP), a biologically important coenzyme, participates in several enzymatic reactions, and its marginal deficiency in the human body can cause cardiovascular disease. However, the excess accumulation of the nonessential Al3+ metal ion in the human body can also cause serious health problems. Therefore, there is significant interest in the detection and monitoring of both PLP and Al3+. This paper introduced a red-emitting dual-ligand co-functionalized copper nanoclusters beta-CD-GSH-CuNCs for the simultaneous detection of PLP and Al3+. The capped beta-cyclodextrin (beta-CD) in beta-CD-GSH-CuNCs selectively recognizes PLP by forming a host-guest inclusion complex that caused fluorescence quenching at 625 nm with the formation of an emission band at 488 nm. The ratiometric fluorescence from beta-CD-GSH-CuNCs allowed to detect PLP down to 5.29 mu M. Further, the in situgenerated nano-assembly beta-CD-GSH-CuNCs@PLP showed a selective turn-on fluorescent response for Al3+. The complexation-induced aggregation of nano-assembly resulted in strong fluorescence enhancement at 451 nm that allowed to detect Al3+ down to 0.187 mu M. The analytical utility of beta-CD-GSH-CuNCs@PLP was validated as a nanoprobe by monitoring Al-3(+) concentrations in real environmental water samples.

Automated summary

A dual-ligand co-functionalized copper nanocluster nanoprobe was developed for the simultaneous detection of PLP and Al3+, showing promising capabilities for real-time monitoring of these substances in environmental water samples.