The electrochemical sensor based on triblock polyadenine-based probe and copper nanoclusters for the robust detection of HPV16 gene

Abstract

The cervical cancer is the fourth most common cancer among women worldwide. Human papillomavirus type 16 (HPV16) is one of the common biomarkers which cause the cervical cancer. In this work, an electrochemical sensor based on a triblock polyadenine-based probe (TPP) and copper nanoclusters (CuNCs) was constructed for the rapid, sensitive and selective detection of HPV16. The TPP contained the central polyadenine (PolyA) segment and two flanking DNA probes. The middle PolyA segment had a high affinity to the gold electrode surface, leading to the adjustable density of the TPP by the length of PolyA. When the DNA template that mediated the formation of CuNCs was introduced, the DNA template partly hybridized with the two flanking DNA probes of the TPP. A large number of CuNCs were synthesized on the DNA template, producing a big electrochemical impedance signal. When the target DNA (HPV16) was present, it bound to the two flanking DNA probes of the TPP, which resulted in the release of the DNA template from the electrode and produced a small electrochemical impedance signal. The limit of detection (LOD) for the detection of HPV16 was 3.34 pM and the linear range was 10 pM - 10 μM. The designed sensor demonstrated good sensitivity, good selectivity, and satisfied recovery, providing the valuable insights in the cervical cancer prevention and the development of the electrochemical biosensors.