A Simple and Rapid Phosphorescence Probe Based on Mn-Doped ZnS Quantum Dots for Chloramphenicol Detection

Abstract

An innovative phosphorescence probe based on Mn-doped ZnS quantum dots (Mn:ZnS QDs) was developed for selective detection of chloramphenicol (CAP) via inner-filter effect (IFE). Mn:ZnS QDs were synthesized by water method and modified with L-Cysteine for better stability, and the average diameter of the nanometer particle was 3.8[Formula: see text]nm. With the excitation wavelength at 289[Formula: see text]nm, the strong phosphorescence of Mn:ZnS QDs can be emitted at 583[Formula: see text]nm. The excitation spectrum of Mn:ZnS QDs was substantially overlapped with the absorption spectrum of the target CAP. The excited light of Mn:ZnS QDs can be absorbed partially by CAP when they coexist, the phosphorescence intensity decreased with the increasing concentration of CAP, and it has a good linear relationship. Under optimal conditions, the linear relational concentration range achieved four orders of magnitude from 25 to [Formula: see text] ([Formula: see text]), with a detection limit (LOD; [Formula: see text]) down to 0.81[Formula: see text][Formula: see text]. The simple, rapid and low cost IFE phosphorescent probe exhibited satisfactory recoveries ranging from 88.9% to 98.5% for CAP analysis in spiked honey, which shows a potential for routine screening of CAP in ensuring the food safety.