Rapid Purification and Enrichment of Viral Particles Using Self-Propelled Micromotors

Virus infections remain one of the principal causes of morbidity and mortality worldwide. The current gold standard approach for diagnosing pathogens requires access to reverse transcription–polymerase chain reaction (RT‒PCR) technology. However, separation and enrichment of the targets from complex and diluted samples remains as a major challenge. In this work, we proposed a micromotor-based sample preparation concept for the efficient separation and concentration of target viral particles before PCR. The micromotors are functionalized with antibodies with a 3D polymer linker and are capable of self-propulsion by the catalytic generation of oxygen bubbles for selective and positive virus enrichment. This strategy significantly improves the enrichment efficiency and recovery rate of virus (up to 80% at 104 tu mL-1 in a 1 mL volume within just 6 min) without external mixing equipment. The method allows the Ct value in regular PCR tests appearing 6-7 cycles earlier and a detection limit of 1 tu mL-1 for target virus from swap samples. A point-of-need test kit is designed based on the micromotors which can be readily applied to pretreat a large volume of samples.