Ternary nanocube-based off-on blinking-type electrochemiluminescence towards enzyme-free detection of hepatitis B virus (HBV)-related DNA

Hepatitis B virus (HBV) infection remains a global public health problem, which is directly associated with a very high risk of evolving into liver cirrhosis and hepatocellular carcinoma (HCC). So far, enzyme-linked immunosorbent assay (ELISA) is still a main detection method for HBV infection in hospital, by which it enables to identify HBV infection in vitro through detection of circulating hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). However, ELISA requires antibody-dependent and enzyme-labeling. What's worse, ELISA is silent to the type of occult HBV infection, which does not express HBsAg. Thus, it is of significance to establish a favorable alternative to detect HBV-related specific DNA rather than proteins, as well as to avoid antibody and enzyme-labeling assay for unambiguous screening of HBV infection. Herein, we have exploited a ternary nanocube (AgAuPt NCs)-based off-on blinking-type electrochemiluminescence (ECL) biosensor towards detection of HBV-related DNA for the first time, integrated with Pb2+-requiring DNAzyme recycling amplification. By this way, the detection limit down to 65 aM is achieved. The unique off-on blinking-type ECL biosensor not only overcomes the drawbacks of ELISA towards detection for HBV infection but also provides a potential for clinical application.