Ultrasensitive PCR-Free detection of whole virus genome by electrochemiluminescence

Detection of nucleic acids is crucial in many medical applications, and in particular for monitoring infectious diseases, as it has become perfectly clear after the pandemic infection of COVID-19. In this context, the development of innovative detection methods based on signal-amplification rather than analyte-amplification represents a significant breakthrough compared to existing PCR-based methodologies, allowing the development of new nucleic acid detection technologies suitable to be integrated in portable and low-cost sensor devices while keeping high sensitivities, thus enabling massive diagnostic screening. In this work, we present a novel molecular sensor for the ultrasensitive PCR-free detection of Hepatitis B Virus (HBV) based on electrochemiluminescence (ECL). Thanks to the combination of surface cooperative hybridization scheme with ECL detection strategy, our novel DNA sensor is able to detect HBV genome - both synthetic and extracted - with the unprecedented limit of detection (LoD) of 0.05 cps μL^-1 for extracted sample, that is even lower than the typical LoD of PCR methodologies. The detection concept presented here for HBV detection is very versatile and can be extended to other pathogens, paving the way for future development of rapid molecular test for infectious diseases, both viral and bacterial, in Point-of-Care (PoC) format.