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

Abstract

Covalent organic frameworks (COFs) with unique structural merits show substantial potential in the construction of biosensors. However, high‐performance COF‐based biosensors have rarely been reported due to special requirements for electrochemical biosensing. Here, the ultrathin nitrogen and sulfur‐rich bithiazole‐based COF nanosheets (COF‐Bta‐NSs) with the thickness of ≈1.95 nm are developed by using an interfacial perturbation growth strategy, and are further integrated with acetylcholinesterase (AChE) through strong supramolecular interactions to construct a high‐performance biosensor for organophosphorus pesticides (OPs) detection. By virtue of the excellent electrical conductivity and abundant edge unsaturated sites of COF‐Bta‐NSs, such unique biosensors can be used for the detection of various OPs, showing a wide detection range, ultralow detection limit, and high stability. Significantly, the portable biosensing device is further set up based on commercialized screen‐printed electrode (SPE), which is sensitive and reliable with the actual samples collected from river water and leafy vegetables, confirming the practical applicability. This research provides a novel insight into the development of advanced COF‐based biosensors with excellent performance for biological and environmental analysis.

Symmetrical Localized Built-in Electric Field by Induced Polarization Effect in Ionic Covalent Organic Frameworks for Selective Imaging and Killing Bacteria

“…The interlamellar spacing was 3.48 Å. The loosely bound chloride ions and positive charge of guanidinium units can disturb the π–π stacking interactions during the formation of the BPTG Cl structure, which decreased the crystallinity. , In addition, the simulated data, structural models, and unit cell parameters for BPTG Cl COF with AA stacking pattern are shown in Figure S9 and Table S2.…”

Enzyme Immobilization using Covalent Organic Frameworks: From Synthetic Strategy to COFs Functional Role

“…(B) Hydrogen-bonded bridges between the COF organic linkers and enzyme residual groups. Reproduced with permission from Wei et al Copyright 2023 Wiley-VCH. (C) Preparation of enzyme-Fe 3 O 4 @COF biocomposites used for tandem catalysis.…”

COF-Coated Microelectrode for Space-Confined Electrochemical Sensing of Dopamine in Parkinson’s Disease Model Mouse Brain

“…COF is a kind of crystalline porous organic material possessing a high surface area, a controllable structure, and adjustable pore size, which has been employed to fabricate various electrochemical sensors in recent years. , To ingeniously modulate the structures and properties of COF by using different monomers, the stability, selectivity, and sensitivity of functionalized electrochemical sensors can be precisely controlled and enhanced. A variety of substances including metal ions, neurotransmitters, drugs, disease metabolites and explosives in water, biofluids, or tissues can be detected by COF-based electrochemical sensors. , For example, Zhu et al modified the screen-printed electrode with an ultrathin bithiazole-based COF for the detection of organophosphorus pesticides, attaining a high sensitivity and low limit of detection . Lu et al fabricated a kind of biocompatible two-dimensional (2D) conductive COF with abundant carbonyl groups to modify the glassy carbon electrode for detecting paraoxon .…”

“…42,43 For example, Zhu et al modified the screen-printed electrode with an ultrathin bithiazole-based COF for the detection of organophosphorus pesticides, attaining a high sensitivity and low limit of detection. 44 Lu et al fabricated a kind of biocompatible two-dimensional (2D) conductive COF with abundant carbonyl groups to modify the glassy carbon electrode for detecting paraoxon. 45 We have recently synthesized COFs with tunable lipophilicity to modify the electrode, realizing the selective detection of vitamin A and vitamin C in the multivitamin tablets.…”