Non-sticky SiNx nanonets for single protein denaturation analysis†

Abstract

Proteins play crucial roles in nearly all biological activities, with their functional structures deriving from stable folded conformations. Protein denaturation, induced by chemical and physical agents, is a complex process where proteins lose their stable structures, thereby impairing their biological functions. Characterizing protein denaturation at the single-molecule level remains a significant challenge. In this study, we developed non-adhesive silicon nitride nanonets coated with polyethylene glycol to capture individual proteins. We utilized these nanonets to investigate the denaturation of ovalbumin induced by guanidine hydrochloride (Gdn-HCl) and lead chloride. The entire denaturation and renaturation processes of a single ovalbumin molecule were monitored via ionic current measurements through the nanonets. These non-sticky nanonets offer a versatile tool for real-time studies of structural changes during protein denaturation.