A target analyte induced fluorescence band shift of piperazine modified carbon quantum dots: a specific visual detection method for oxytetracycline

Through the protection/deprotection of one amine group and the amidation reaction, piperazine was used to modify carbon quantum dots (CQDs) and successfully served as a medium to combine oxytetracyclines (OTC) in solution by hydrogen bonding and electrostatic interactions. Fluorescence resonance energy transfer (FRET) probably occurred between piperazine modified CQDs (P-CQDs) and combined OTC, which resulted in the red-shift of the fluorescence band. Besides superior specificity for examining, a good linear relationship between the maximum emission wavelength of P-CQDs and concentrations of OTC (0 to 10 mu M) can be obtained, which provides a rapid and convenient visual fluorescence detection method of OTC.