A regenerable electrochemical biosensor based on the consecutive adenines immobilization and CuNCs for the sensitive detection of HPV16 DNA

Human papillomavirus 16 (HPV16) is a subtype of high-risk human papillomavirus and is closely associated with approximately 50% of cervical cancers and certain other cancers of the reproductive system.This work developed a regenerable electrochemical biosensor based on the consecutive adenines (PolyA) immobilization and copper nanoclusters (CuNCs) for the sensitive detection of HPV16 DNA.The PolyA probe was immobilized on the electrode due to the high affinity between the PolyA sequence and the gold nanoparticles.Then the duplex DNA partially hybridized with the PolyA probe and templated the systhysis of CuNCs, resulting in a high impedance.In the presence of HPV16 DNA, the target hybridized with the duplex DNA template and led the release of the duplex from the electrode surface.The amount of the CuNCs thus decreased and a low impedance was obtained.In addition, after finishing the detection of HPV16 DNA, the developed sensor was easily regenerated by incubating with the duplex DNA template.The Au-S based and the PolyA based unregenerable biosensors were also developed for the HPV16 DNA assay in this work.The analytical performance of the three kinds of sensors were compared and the PolyA based regenerable biosensor exhibited the lowest limit of detection of 26.49 pM.Moreover, the developed regenerable biosensor performed the satisfactory repeatability, reproducibility, selectivity, regenerability and recoveries.It will have important applications in the sensitive and selective electrochemical determination of other DNA and targets.