Ultrathin Conductive Bithiazole-Based Covalent Organic Framework Nanosheets for Highly Efficient Electrochemical Biosensing

摘要

Covalent organic frameworks (COFs) with unique structural merits showsubstantial potential in the construction of biosensors. However,high-performance COF-based biosensors have rarely been reported due tospecial requirements for electrochemical biosensing. Here, the ultrathinnitrogen and sulfur-rich bithiazole-based COF nanosheets (COF-Bta-NSs) withthe thickness of ≈1.95 nm are developed by using an interfacial perturbationgrowth strategy, and are further integrated with acetylcholinesterase (AChE)through strong supramolecular interactions to construct a high-performancebiosensor for organophosphorus pesticides (OPs) detection. By virtue of theexcellent electrical conductivity and abundant edge unsaturated sites ofCOF-Bta-NSs, such unique biosensors can be used for the detection ofvarious OPs, showing a wide detection range, ultralow detection limit, andhigh stability. Significantly, the portable biosensing device is further set upbased on commercialized screen-printed electrode (SPE), which is sensitiveand reliable with the actual samples collected from river water and leafyvegetables, confirming the practical applicability. This research provides anovel insight into the development of advanced COF-based biosensors withexcellent performance for biological and environmental analysis.