The DNAzyme-Driven Catalytic Hairpin Self-Assembly for the CuNCs‑Based Electrochemical Detection of HPV16 DNA

Abstract

High-risk human papillomavirus (HPV), particularly HPV16, is a major causative factor in cervical cancer. Its early and highly sensitive detection is crucial for reducing the cancer mortality rates among women. The traditional detection methods suffered from the limitations such as complex procedures and low sensitivity. To solve the issue, this work developed a copper nanoclusters (CuNCs)-based electrochemical biosensor combined with the DNAzyme-driven catalytic hairpin self-assembly (CHA) signal amplification strategy for the highly sensitive detection of HPV16 DNA (deoxyribonucleic acid). In the presence of HPV16 DNA, the duplex formed between a DNA probe and the Cu-substrate was opened, and the Cu-substrate was released. The released Cu-substrate then underwent specific cleavage in the presence of the Cu-enzyme and Cu2+, generating two DNA fragments, S1 and S2. The S1 subsequently initiated the CHA cycle, producing a large amount of the duplex formed by two hairpin strands (i.e., H1/H2). The H1/H2 duplex were then bound to the polyadenine (PolyA) probe on the electrode surface, resulting in the in situ synthesis of CuNCs and generating a significantly amplified impedance signal. The results demonstrated that the developed sensor exhibited high sensitivity, good selectivity and satisfactory recovery for the HPV16 DNA detection, which was simple, economical and efficient.