Development of a colorimetric biosensor based on G-quadruplex aptamer and gold nanoparticles for rapid and sensitive detection of HPV18

Abstract

Human papillomavirus (HPV), the most prevalent sexually transmitted infection and a leading cause of cervical cancer, often lacks rapid and cost-effective diagnostic methods. This study introduces a novel colorimetric biosensor for specific and sensitive HPV18 detection. This biosensor was developed using an in silico-designed G-quadruplex aptamer, chosen for its inherent stability and specific binding capabilities, in conjunction with gold nanoparticles (AuNPs). Our in silico design identified APT43 as the top candidate aptamer, demonstrating high binding affinity and specificity for the HPV18 L1 protein via molecular docking. AuNPs were then experimentally synthesized and functionalized with APT43. Successful conjugation was confirmed by DLS characterization, evidenced by a hydrodynamic size increase from ∼29 nm to ∼36 nm and a zeta potential shift from −36 mV to −29.8 mV. The developed biosensor exhibited high specificity for HPV18, showing no cross-reactivity with types 16, 11, or 6. It also achieved a remarkably low detection limit of 85 viral copies/mL, significantly lower than the typical ∼1000 copies/mL reported for many commercial PCR kits. This rapid, visual, aptamer-induced AuNP aggregation system offers a sensitive, specific, and cost-effective diagnostic tool for HPV18, particularly beneficial in resource-limited settings. This work reports the first computationally designed aptamer capable of type-specific discrimination of HPV18 from other high- and low-risk HPV types in real clinical samples, marking a significant advancement in rapid HPV diagnostics. © 2026 Elsevier B.V.