Development of a new fluorescent probe for methylglyoxal determination in foods and living zebrafish.

Abstract

This study presents the development of a novel fluorescent probe, referred to as the Hydroxyflavone-Tethered Methylglyoxal Probe (HT-MGO), designed for the detection of methylglyoxal (MGO). The probe structure incorporates a butylamine-modified o-phenylenediamine recognition moiety in conjunction with a flavonoid fluorophore. HT-MGO operates through a photoinduced electron transfer (PET) mechanism, in which the flavonol functions as the fluorophore and the quinoxaline acts as the quenching group. The introduction of a butylamine moiety into the o-phenylenediamine backbone significantly enhanced the selectivity of the probe for detecting the target molecule MGO by modulating steric hindrance. HT-MGO was employed to quantify MGO in various commercially available biscuits, establishing a standard curve that delineates both the linear response range and detection sensitivity of HT-MGO (the limit of detection (LOD) as low as 0.337 μg/kg, and the limit of quantification (LQD) as low as 1.01 μg/kg). Using an external standard method, HT-MGO quantified the levels of MGO in three commercially available bakery biscuits, which were found to range from 4.24 mg/kg to 5.09 mg/kg. Furthermore, HT-MGO was successfully utilized for imaging MGO in live zebrafish, where a significant and concentration-dependent fluorescence quenching was observed in the red channel following treatment with exogenous MGO (20 and 40 μM), thereby visually demonstrating the probe's ability to respond to MGO within a complex biological system.