Protein-templated gold nanoclusters based sensor for off–on detection of ciprofloxacin with a high selectivity

In this contribution, bovine serum albumin stabilized gold nanoclusters as novel fluorescent probes were successfully utilized for the detection of ciprofloxacin for the first time. Our prepared gold nanoclusters exhibited strong emission with peak maximum at 635 nm. Cu2+ was employed to quench the strong fluorescence of the gold nanoclusters, whereas the addition of ciprofloxacin caused the fluorescence intensity restoration of the Cu2+–gold nanoclusters system. The increase in fluorescence intensity of Cu2+–gold nanoclusters system caused by ciprofloxacin allows the sensitive detection of ciprofloxacin in the range of 0.4 ng mL−1 to 50 ng mL−1. The detection limit for ciprofloxacin is 0.3 ng mL−1 at a signal-to-noise ratio of 3. The present sensor for ciprofloxacin detection possesses a low detection limit and wide linear range. In addition, the real samples were analyzed with satisfactory results.

► We have prepared protein-templated gold nanoclusters.
► The gold nanoclusters exhibited strong emission with peak maximum at 635 nm.
► Cu2+ quenched the strong fluorescence of the gold nanoclusters.
► Ciprofloxacin induced the fluorescence restoration of the Cu2+–nanoclusters system.
► A novel ciprofloxacin assay has been developed.