Ratiometric Fluorescent Probe Based on Diazotization-Coupling Reaction for Determination of Clenbuterol

Abstract

In view of the potential harm caused by illegal feeding of clenbuterol (CLB) in the livestock industry, herein, a novel ratiometric fluorescent probe based on graphene quantum dots (GQDs)@[Ru(bpy) 3 ] 2+ was elaborately constructed for CLB detection. In this probe, GQDs acted as response signals, and their fluorescence was remarkably quenched by CLB through the diazotization-coupling reaction. As for [Ru(bpy) 3 ] 2+ as a reference signal, its fluorescence was hardly affected. The intensity ratio of two fluorophores showed good linearity with CLB concentration in the range of 0.05−40 μM, accompanied by visualization of fluorescence variation from yellow to red. The detection limit was as low as 0.029 μM. Particularly, the probe was successfully used to detect CLB in pork and beef samples with satisfactory recoveries. To our knowledge, this is the first report on a ratiometric fluorescent probe for the detection of CLB, which possesses broad application prospects in food safety risk monitoring.

Sensitive and Selective Detection of Clenbuterol in Meat Samples by a Graphene Quantum Dot Fluorescent Probe Based on Cationic-Etherified Starch

“…Liu et al found that the fluorescence of GQDs could be quenched by CLB through the diazotization-coupling reaction. The decrease in fluorescence intensity was explained by the change in the absorption spectrum of GQDs after the addition of CLB to the diazotization reaction, and the quenching mechanism was investigated by the change in fluorescence lifetime before and after the addition of CLB [43]. We measured the fluorescence lifetime of the N-GQDs solution before and after the addition of CLB (50 µL, 10 −5 M), and the test instrument was Edinburgh FLS 1000, as seen in Figure 4d.…”

Recent progress on graphene quantum dots‐based fluorescence sensors for food safety and quality assessment applications

“…The detection method showed an LOD of 10 −10 g/ml for clenbuterol. Recently, Liu et al developed a ratiometric GQDs fluorescent probe based on diazotization-coupling reaction for sensitive determination of clenbuterol (Liu et al, 2020). In this sensing probe, GQDs acted as the response signals, and upon the addition of clenbuterol, their fluorescence was remarkably quenched owing to the diazotization-coupling reaction.…”

“…(b) Optical photos of solutions of GQDs (vial 1) and GQDs in the presence of melamine (vial 2) or Hg 2+ (vial 3), and of GQDs-Hg 2+ in the presence of 0.2, 0.8, and 2.0 ppm melamine for vials 4, 5, and 6, respectively, taken under a 365-nm UV lamp (reproduced fromLi et al [2014] with permission from ACS). (iv) Schematic depicting the GQDs@[Ru(bpy) 3 ] 2+ -based ratiometric fluorescent probe for clenbuterol detection (reproduced fromLiu et al [2020] with permission from ACS)…”

A portable smartphone platform utilizing dual-sensing signals for visual determination of semicarbazide in food samples

“…Generally, a ratiometric fluorescent probe is a promising tool for naked-eye detection due to reduced environmental interference and distinguished color variations. [33][34][35] Chromophore reaction-based fluorescent probes show distinct colorimetric and ratiometric fluorescent signals by drastic conjugation length changes of chromophores. 36,37 For instance, the core of BODIPY, pyrrolopyrrole aza-BODIPY (PPAB), and pyrrolopyrrole cyanine (PPCy) was susceptible to being attacked by nucleophiles such as a base, hydrazine, and organic amine.…”