A label free nanosensing platform for the detection of cervical cancer through analysis of ultratrace DNA hybridization

Cervical cancer is a major health problem caused by human papillomavirus (HPV) infection which affects more than 500,000 women every year worldwide. Majority of the cases occur in less developed countries since there are lack of availability of effective screening methods for diagnosis. Therefore, a fast, accurate and early detection platform is developed for HPV detection. The current study describes a sensitive, specific, easy and a cost-effective label free DNA based electrochemical biosensor for HPV-16 detection. Detection of HPV-16 is performed by an electrochemical platform coated with chitosan capped gold nanoparticles (ccAuNPs). These nanoparticles were characterized using Ultraviolet–visible (UV–vis) analysis, Fourier Transfer Infrared Ray analysis (FT-IR) and Transmission Electron Microscope (TEM). The probe DNA (PDNA) was then immobilized onto the nanoparticle modified electrode and hybridized with target DNA (TDNA). The electrochemical analysis was done at each step of modification using cyclic voltammetry (CV) and square wave voltammetry (SWV). The biosensor responds to TDNA concentration range from 1 pM to 1 μM and the limit of detection is 1 pM with the sensitivity of 0.39 mA pM−1. This proposed biosensor achieved good performance of the PDNA/ccAuNPs modified ITO electrode. The results illustrate that the developed nanotechnology-based electrochemical DNA biosensor provides very low detection limit in picomolar level. It also exhibited excellent selectivity and stability, which is important for potential applications in the onsite analysis of HPV-16 and in medical diagnosis.