The capsid assembly-induced luminescence enhancement (AILE) of DNA-protected silver nanoclusters and an in situ application

Abstract

Two assembly modes have been constructed between double-strand DNA-protected silver nanoclusters (AgNCs-dsDNA) and human papillomavirus (HPV) 16 main capsid protein L1, respectively, which are well defined by CsCl gradient centrifugation, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The co-assembly leads to a large emission increase of AgNCs-dsDNA attributed to an assembly-induced luminescence enhancement (AILE), and vice versa in disassembly; however, the post-assembly does not. Therefore, a new approach to monitoring the assembly/disassembly of HPV virus-like particles (VLPs) is established accordingly. The study not only presents an AILE phenomenon for silver nanoclusters but also affords an easily performed fluorescence approach to evaluate HPV VLP assembly/disassembly directly, which could be extended to other kinds of metal nanoclusters protected by DNA as well as a kinetic study on the assembly of other species of virus.