1.Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials,Wuhan,China;2.Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering,Hubei University,Wuhan,China;3.Hubei Province Key Laboratory of Regional Development and Environment Response,Wuhan,China
Abstract:
Stable copper nanoclusters (CuNCs) were prepared by utilizing D-penicillamine as both the stabilizer and reductant. The emission of the CuNCs (with excitation/emission peaks at 390/645 nm) is largely stabilized by coating with poly(sodium-p-styrenesulfonate) (PSS). Cytochrome c (Cyt c) quenches the fluorescence of the PSS-coated CuNCs, and this effect was exploited to design a quenchometric fluorometric assay for Cyt c. If trypsin is added to the loaded CuNCs, it will hydrolyze Cyt c to form peptide fragments, and fluorescence is gradually restored. A highly sensitive and fluorometric turn-off-on assay was constructed for sequential detection of Cyt c and trypsin. The linear ranges for Cyt c and trypsin are from 8.0 nM to 680 nM, and from 0.1 to 6.0 μg mL?1, and the lower detection limits are 0.83 nM and 20 ng mL?1 for Cyt c and trypsin, respectively.
Graphical abstract Schematic illustration of the fluorometric assay for trypsin based on the electron transfer between poly(p-styrenesulfonate)-protected copper nanoclusters (PSS-CuNCs) and cytochrome c (Cyt c).
