Determination of Tigecycline by Quantum Dots/Gold Nanoparticles-based Fluorescent and Colorimetric Sensing System

In this study, two simple and sensitive methods for detection of tigecycline are developed based on thioglycolic acid-capped CdTe quantum dots (TGA-CdTe QDs) and unmodified gold nanoparticles (AuNPs), respectively. The first method was based on the fluorescence quenching of CdTe QDs by the addition of tigecycline. For the second method, the introduction of tigecycline could induce the aggregation of gold nanoparticles, displaying distinct changes in color and in UV-vis spectra. Under optimal conditions, the relative fluorescence intensity of CdTe QDs decreased linearly with the increasing concentration of tigecycline in the range of 0.11-35.56 ug mL-1 with a detection limit of 3.93×10-2 ug mL-1. While the colorimetric sensor could detect tigecycline in linear range from 5.98×10-3 to 1.44×10-1 ug mL-1 and from 0.30 to 2.99 ug mL-1 with a detection limit of 1.07×10-3 ug mL-1. Moreover, both the proposed methods were applied to real sample with satisfactory results. Finally, comparisons between these two methods were made.