A highly selective fluorescent sensor for chlortetracycline based on histidine-templated copper nanoclusters.

[Display omitted] • In this paper, the histidine-fabricated copper nanoclusters (Cu NCs@His) was first developed to detect chlortetracycline. • The developed probe exhibited a wide linear range and a lower detection limit towards chlortetracycline. • Quenching mechanisms were the static quenching and inner filter effect. • This proposed method has been applied for the detection of chlortetracycline in real samples. In this study, histidine-protected copper nanoclusters (Cu NCs@His) were established by using a one-pot method, which histidine and ascorbic acid were applied as the template and reducing agent, respectively. The as-developed Cu NCs@His endued green emission wavelength at 494 nm with the excitation of 378 nm. The Cu NCs@His exhibited green fluorescence under UV light (365 nm). Using Cu NCs@His as a pattern nanosensor, the fluorescent "turn off" mechanism was fabricated for the determination of chlortetracycline in the light of the linear decrease of fluorescence intensities around 494 nm. The chlortetracycline conducted as a quencher, leading to reveal an excellent linear relationship between ln(F 0 /F) of Cu NCs@His and chlortetracycline concentrations with the range of 0.5–200 μM, and the detection limit was 0.876 μM. The fluorescence quenching of Cu NCs@His revealed excellent selectivity for chlortetracycline over other potential interfering substances in the human body. This strategy was exhibited to be a convenient sensing platform for the detection of chlortetracycline in real medical samples, which could unfold a brand new and direct system for the sensing of chlortetracycline in real samples. [ABSTRACT FROM AUTHOR]