Polydopamine (PDA)-based molecular imprinting photoelectrochemical (MIP-PEC) sensor is usually applied to recognize proteins. However, the abundant active functional groups on the PDA surface lead to a non-specific adsorption at the non-imprinted sites, resulting in a decrease in the ability of the MIP-PEC sensor to qualitatively analyze proteins. Here, a light-trapping silicon electrode was successively modified on its surface by a buried junction, nitrogen-doped carbon and TiO2 (TiO2/CN/SiP), amplifying its photoelectric signal and improving its detection sensitivity. Meanwhile, a MIP layer, based on the functional monomer of dopamine and the template of BSA, was assembled on TiO2/CN/SiP. In addition, the non-imprinted sites of the MIP layer were blocked by the introduction of polymer brushes, and this blocking could reduce a probability of the non-specific adsorption. The experimental results suggest that the specific recognition ability of the MIP-PEC sensor to BSA was significantly improved with an increase of imprinting factor from 5.10 to 7.06. Also, the sensing signals showed a good linearity with BSA concentration in a range of 10-16-10-9 mg·mL-1, and a limit of detection of 2.203×10-17 mg·mL-1 (S/N=3). Furthermore, it was also successful to analysis as the template of acetylcholine was used, confirming the universality of this method.
A Lewis-acid-mediated intramolecular trifluoromethylthiolation of alkenes with phenols that can offer direct access to SCF3-containing chromane and dihydrobenzofuran compounds was disclosed for the first time. Numerous SCF3-containing chromanes were obtained in moderate to good yields using γ-substituted 2-allyphenols as substrates. Meanwhile, various SCF3-containing dihydrobenzofurans with oxa-quaternary centers were also delivered in moderate to good yields using β-substituted 2-allyphenols as substrates.
Abstract Background The outbreak of SARS-CoV-2 continues to pose a serious threat to human health and social. The ongoing pandemic of COVID-19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made a serious threat to public health and economic stability worldwide. Given the urgency of the situation, researchers are attempting to repurpose existing drugs for treating COVID-19. Methods We first established an anti-coronavirus drug screening platform based on the Homogeneous Time Resolved Fluorescence (HTRF) technology and the interaction between the coronavirus S protein and its host receptor ACE2. Two compound libraries of 2,864 molecules were screened with this platform. Selected candidate compounds were validated by SARS-CoV-2_S pseudotyped lentivirus and ACE2-overexpressing cell system. Molecular docking was used to analyze the interaction between S-protein and compounds. Results We identified three potential anti-coronavirus compounds: tannic acid (TA), TS-1276 (anthraquinone), and TS-984 (9-Methoxycanthin-6-one). Our in vitro validation experiments indicated that TS-984 strongly inhibits the interaction of the coronavirus S-protein and the human cell ACE2 receptor. Additionally, tannic acid showed moderate inhibitory effect on the interaction of S-protein and ACE2. Conclusion This platform is a rapid, sensitive, specific, and high throughput system, and available for screening large compound libraries. TS-984 is a potent blocker of the interaction between the S-protein and ACE2, which might have the potential to be developed into an effective anti-coronavirus drug.
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