Virus-like Plasmonic Nanoprobes for Quick Analysis of Antiviral Efficacy and Mutation-Induced Drug Resistance.

As the pathogenic viruses and the variants of concern greatly threaten human health and global public safety, the development of convenient and robust strategies enabling rapid analysis of antiviral drug efficacy and mutation-induced resistance is quite important to prevent the spread of human epidemics. Herein, we introduce a simple single-particle detection strategy for quick analysis of anti-infective drugs against SARS-CoV-2 and mutation-induced drug resistance, by using the wild-type and mutant spike protein-functionalized AuNPs as virus-like plasmonic nanoprobes. Both the wild-type and mutant virus-like plasmonic nanoprobes can form core-satellite nanoassemblies with the ACE2@AuNPs, providing the opportunity to detect the drug efficacy and mutation-induced resistance by detecting the changes of nanoassemblies upon drug treatment with dark-field microscopy. As a demonstration, we applied the single-particle detection strategy for quantitative determination of antiviral efficacy and mutation-induced resistance of ceftazidime and rhein. The mutations in the receptor-binding domain of Omicron variant could lead to an increase of EC 50 values of ceftazidime and rhein, formerly from 49 and 57 μM against wild-type SARS-CoV-2, to 121 and 340 μM, respectively. The mutation-induced remarkable decline in the inhibitory efficacy of drugs was validated with molecule docking analysis and virus-like plasmonic nanoprobe-based cell-incubation assay. Due to the generality and feasibility of the strategy for the preparation of virus-like plasmonic nanoprobes and single-particle detection, we anticipated that this simple and robust method is promising for the discovery and efficacy evaluation of anti-infective drugs against different pathogenic viruses.