Protein protected gold nanoclusters have outstanding physical and chemical properties that make them excellent scaffolds for the construction of novel chemical and biological probes. In this study, a simple one-pot synthesis method was proposed for the preparation of fluorescent probes based on ovalbumin-stabilized gold nanoclusters. This strategy allowed the generation of water-soluble gold nanoclusters within 5 min. The as-prepared fluorescent probe exhibited a red fluorescence emission at 625 nm, and good thermostability. The fluorescent probe was applied to measure glucose concentrations based on the hydrogen peroxide-induced fluorescence quenching principle, and showed favorable biocompatibility, high sensitivity and good selectivity. As a result of the advantageous properties and performance of this fluorescent probe, the present assay allowed for the selective determination of glucose in the range of 5.0×10-6 to 10.0×10-3 mol/L with a detection limit of 1.0×10?6 mol/L. Moreover, the glucose content in urinary samples was analyzed using the constructed fluorescent probe: this indicated the potential of the fluorescent gold nanoclusters for applications in biological and clinical diagnosis and therapy.
Herein, a novel probe based on poly(N,N′-methylenebisacylamide) protected Au NPs(PDMAM-Au NPs) was developed for determination of silver ions. The thiol-terminated PDMAM was synthesized by the reversible addition fragmentation chain transfer radical polymerization. Then, the PDMAM-Au NPs were prepared by a simple, one-pot and green process. It has been observed that existence of the silver ions evoked a small red-shift to the emission peak of PDMAM-Au NPs and an obvious increase in UV absorption. The detection limit of the present method for silver ions was 0.5 ?mol/L, with a linear range of 1.0–1000 ?mol/L. Moreover, the possible mechanism for enhanced UV absorption intensity with enlarged diameter of PDMAM-Au NPs was explored and discussed briefly. The results demonstrated that silver ions could be detected by the PDMAM-Au NPs based colorimetric assays, further opening up new ways for the visualization and quantification of silver ions involved in our daily life.
