A chemo‐enzymatic colorimetric cascade for detecting ethylene glycol contamination

Ethylene glycol (EG) detection is essential for medical diagnostics and food safety control. EG is also released during polyethylene terephthalate (PET) depolymerization catalyzed by PET hydrolases, making EG quantification a valuable indicator of PET hydrolase activity. Here we developed a colorimetric EG detection assay based on a chemo‐enzymatic cascade involving alcohol dehydrogenase and selective chemical reactions. Incorporation of an auxiliary cofactor regeneration system enhanced the detection sensitivity 32‐fold, yielding excellent analytical performance with linearity ( r 2 = 0.9952) and a limit for detection of 52.84 ± 0.88 μ m . The cascade was successfully applied to a colorimetric PET hydrolase assay, with the validation performed by gas chromatography–flame ionization. Furthermore, this method could effectively detect EG contamination in sorbitol and human serum matrices. Owing to its efficiency and scalability, this approach shows potential as a high‐throughput tool for measuring PET hydrolase activity and EG contamination in food and clinical applications.