Copper nanoclusters based amplified electrochemical sensing of HPV16 DNA combining with triblock polyadenine probe and hybridization chain reaction

Human papillomavirus type 16 (HPV16) is a significant biomarker for cervical cancer, and its precise detection is vital for diagnosing the disease. The work involved developing an electrochemical sensor by utilizing copper nanoclusters (CuNCs), which integrated triblock polyadenine probe (TPP) and hybridization chain reaction (HCR) for sensitively detecting HPV16 DNA. The TPP was assembled on the electrode owing to the strong affinity between its adenine bases and gold. The absence of HPV16 DNA allowed the capture probe to bind with the hairpin DNA, which triggered HCR and generated a large number of CuNCs, causing a substantial electrochemical impedance signal. However, when there was HPV16 DNA in the reaction system, it could bind specifically to the two flanking probes of TPP, causing the release of the capture probe. Without capture probe, the HCR was unable to be triggered, thus generating a small amount of CuNCs and resulting in a reduced electrochemical impedance signal. With the optimal conditions, the sensor could detect HPV16 DNA within a broad linear range of 1 × 10 −12  M – 1 × 10 −5  M and had a low detection limit of 2.6 × 10 −13  M. A new analytical platform for the sensitive detection of DNA was developed, which exhibited good sensitivity and selectivity.