Relay detection of Cu2+ and bovine serum albumin by a dansyl derivative-based fluorescent probe

A dansyl derivative-based fluorescent probe, namely, DGly, was developed for relay detection of Cu2+ and bovine serum albumin (BSA) with high selectivity and sensitivity. This work demonstrated that introducing metal ions can be an effective way to improve the sensitivity of BSA detection. [Display omitted] •A dansyl derivative-based fluorescent probe (DGly) can relay detection of Cu2+ and bovine serum albumin (BSA).•DGly displayed fluorescence “on–off-on” mode for the detection of Cu2+ and BSA.•The visual color of DGly changed from yellow to dark and then to yellowish white after Cu2+ and BSA were added in sequence.•The detection limits of Cu2+ and BSA were 1.32 and 0.26 μM, respectively. A dansyl derivative-based fluorescent probe, namely, DGly, was developed for relay detection of Cu2+ and bovine serum albumin (BSA) with high selectivity and sensitivity. The fluorescence intensity of DGly at 540 nm displayed “on–off–on” phenomenonafter Cu2+ and BSA were added in sequence. Correspondingly, the solution color changed from yellow to dark and then to yellowish white under 365 nm UV light irradiation; thus, the solution could be detected by the naked eye. The association constant of DGly–Cu2+ was stronger than that of DGly–BSA and DGly–Cu2+–BSA. Hence, BSA was detected after a complex was formed between DGly and Cu2+. The relay detection of Cu2+ and BSA was not influenced by other competitive interferents, and the detection limits of Cu2+ and BSA were 1.32 and 0.26 μM, respectively. Analysis of Cu2+ in real water samples validated the detection performance of the method proposed herein; it achieved satisfactory recovery and relative standard deviation values. This work demonstrated that introducing metal ions can be an effective way to improve the sensitivity of BSA detection.