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Covalent organic framework-based electrochemical aptasensors for the ultrasensitive detection of antibiotics

Wang, Minghua, Hu, Mengyao, Liu, Jiameng, Guo, Chuanpan, Peng, Donglai, Jia, Qiaojuan, He, Linghao, Zhang, Zhihong, Du, Miao
Biosensors & bioelectronics 2019 v.132 pp. 8-16
DNA, ampicillin, aptasensors, electrochemistry, electrostatic interactions, enrofloxacin, imines, melamine, moieties, oligonucleotides, polymerization, surface area
We designed and synthesized a novel covalent organic framework (COF) by condensation polymerization of 1,3,6,8-tetrakis(4-formylphenyl)pyrene and melamine through imine bonds (represented by Py-M-COF). The basic characterizations revealed that the Py-M-COF not only exhibited an extended π-conjugation framework, a large specific surface area (495.5 m2 g−1), big pore cavities, and nanosheet-like structure but also possessed rich functional groups, such as C˭C, C˭N, C˭O, and NH2. These features endowed the Py-M-COF with high charge carrier mobility, further improving the strong immobilization of DNA aptamer strands via π-π stacking interaction and electrostatic interaction. As such, the Py-M-COF-based electrochemical aptasensors are ultrasensitive in detecting different antibiotics, including enrofloxacin (ENR) and ampicillin (AMP), yielding extremely low detection limits of 6.07 and 0.04 fg mL−1 (S/N = 3) toward ENR and AMP, respectively, along with other excellent sensing performances. This biosensing platform based on Py-M-COF has potential applications for the sensitive detection of antibiotics or other analytes by replacing the corresponding aptamers.