Achieving ultrasensitive detection of glyphosate in fruits and vegetables using a triple-mode strategy based on carbon dots nanozymes derived from expired drugs

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2025-02, Vol.326, p.125214, Article 125214
• Main Authors: Wu, Wei, Cheng, Hui-Ling, Huang, Yan-Li, Ni, Chen, Shi, Yu-han, Xu, Zhi-Hong, Zhang, Guo-Qi
• Format: Article
• Language: English
• Subjects: Carbon dots nanozymes; Colorimetric; Fluorescence; Glyphosate; Peroxidase-like activity; Photothermal
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2024.125214

[Display omitted] •Microwave synthesis of stable CDszymes from expired acetaminophen.•Three-mode sensing has lower detection limit for GLP detection.•Triple-mode sensing detected GLP in samples, showing ultra-sensitive detection and drug repurposing potential. Rapid and sensitive detection of glyphosate (GLP) holds significant importance in the monitoring of environmental pollution and potential risks to human health. In this study, carbon dots nanozymes (CDszymes) with peroxidase-like activity were synthesized rapidly using a microwave-assisted method, employing expired drugs as raw materials. In the presence of H2O2, CDszymes catalyze the oxidation of TMB to generate blue oxTMB, which exhibits a photothermal effect under near-infrared light irradiation; an inner filter effect (IFE) may occur between oxTMB and CDszymes. By coupling the cascade catalysis of AChE and ChOx to generate H2O2, GLP effectively inhibits the activity of AChE, constructing a colorimetric/fluorescent/photothermal response platform for GLP. In colorimetry, the detection limit of GLP was 0.33 ng/mL. The detection limits of GLP by fluorescence method and photothermal method were 0.02 ng/mL and 0.41 ng/mL, respectively. The efficacy of this methodology has been successfully demonstrated in fruit and vegetable, it also provides a strategy for the high-value conversion of expired drugs.