Electrochemical DNA biosensor for HPV-16 detection based on novel carbon quantum dots/APTES composite nanofilm

[Display omitted] Schematic representation of the proposed electrochemical DNA biosensor. •Promising for cost-effective cervical cancer screening programs.•Novel electrochemical biosensor detects HPV-16 at ultra-low levels.•Accelerating electron transfer by employing CQDs and APTES.•The orthogonal analysis applied in modifying and optimizing composite nanofilm.•Combines composite nanofilm with engineered HSP for enhanced sensitivity and specificity. Detection of high-risk human papillomavirus (HR-HPV) is critical for early warning and accurate screening of cervical disease in women. Electrochemical biosensors offer a promising analytical strategy that can circumvent the structural complexity of traditional optical components found in current bioassays. In this work, an innovative electrochemical biosensor for HPV-16 detection was developed, utilizing advanced nanomaterial technology and optimized DNA probe grafting processes. The self-assembled composite nanofilm was optimized by conducting an orthogonal analysis. The nanofilm exploited the unique advantages and outstanding performance of (3-aminopropyl)triethoxysilane (APTES) and carbon quantum dots (CQDs), which act as a “molecular bridge” between the biosensing interface and the electrode substrate. The electroactive molecule [Ru(NH3)6]3+ facilitated the highly sensitive signaling of the target DNA by interacting with the double-stranded DNA. Under optimal conditions, the developed electrochemical DNA biosensor exhibited high sensitivity in detecting HPV-16, with a limit of detection (LOD) of 0.73 fM, which showed exceptional potential to be used in widespread point-of-care (PoC) screening programs, opening up new opportunities for various applications.