水溶性钾钠混合聚庚嗪酰亚胺"开-关-开"荧光纤维试纸协同智能手机识别快速检测草甘膦残留OA

Glyphosate is a widely used pesticide exhibiting high environmental stability and potential ecological risks,which necessitates the development of convenient and rapid on-site detection techniques.Traditional methods,while sensitive,are constrained by high instrument costs and long analysis time,making them unsuitable for on-site applications.In this study,water-soluble potassium-sodium mixed poly(heptazine imide)(K,Na-PHI)was synthesized via molten salt synthesis using melamine,KOH,and NaOH as precursors.The resulting water-soluble material exhibited a nanobelt morphology with lateral dimensions of 10‒20 nm and lengths up to micrometers.A novel fluorescence sensing method was thus constructed based on K,Na-PHI,where Cu2+quenched the fluorescence of K,Na-PHI,while glyphosate subsequently restored fluorescence through specific chelation with Cu2+,enabling the quantitative detection of glyphosate.This method exhibited a good linear response to glyphosate over the concentration ranges of 0.001‒0.2 mg/L and 0.2‒30 mg/L,respectively,with a detection limit of 0.5 μg/L.Subsequently,K,Na-PHI was immobilized onto electrospun polyacrylonitrile(PAN)nanofibrous membranes,fabricating K,Na-PHI/PAN fluorescent test strips for on-site detection.By leveraging smartphone color recognition capabilities,this platform successfully achieved real-time,visual,on-site detection of glyphosate(Minimum detectable concentration was 1 μg/L).This study provided an easy-to-operate,fast-responding,and highly sensitive new method for on-site pesticide residue detection,demonstrating significant potential for food safety monitoring applications.