A fluorescence detection of d-penicillamine based on Cu2+-induced fluorescence quenching system of protein-stabilized gold nanoclusters

In this contribution, a luminescent gold nanoclusters which were synthesized by bovine serum albumin as novel fluorescent probes were successfully utilized for the determination of d -penicillamine for the first time. Cupric ion was employed to quench the strong fluorescence of the gold nanoclusters, whereas the addition of d -penicillamine caused obvious restoration of fluorescence intensity of the Cu 2+ -gold nanoclusters system. Under optimum conditions, the increment in fluorescence intensity of Cu 2+ -gold nanoclusters system caused by d -penicillamine was linearly proportional to the concentration of d -penicillamine in the range of 2.0   ×   10 −5 –2.39   ×   10 −4   M. The detection limit for d -penicillamine was 5.4   ×   10 −6   M. With the off–on fluorescence signal at 650   nm approaching the near-infrared region, the present sensor for d -penicillamine detection had high sensitivity and low spectral interference. Furthermore, the novel gold nanoclusters-based fluorescent sensor has been applied to the determination of d -penicillamine in real biological samples with satisfactory results.