Nanoparticle-based colorimetric assays for early and rapid screening of the oncogenic HPV variants 16 and 18

Cervical cancer is predominantly caused by human papillomavirus (HPV), with oncogenic strains HPV 16 and 18 accounting for most cases worldwide. Prompt and precise identification of these high-risk HPV types is essential for enhancing patient outcomes as it enables timely intervention and management. However, the existing HPV detection techniques are time-consuming, expensive, and require highly skilled personnel. This study presents the development and evaluation of a colorimetric nanosensor for the rapid detection of high-risk human papillomavirus (HPV) variants 16 and 18. Gold nanoparticles (AuNPs) were synthesized using an optimized method based on response surface methodology and then functionalized with monoclonal antibodies specific to HPV16-L1 and HPV18-L1 proteins. The nanosensor exhibited a visible color shift from red to violet upon the detection of the target proteins. The analytical validation demonstrated good linearity, sensitivity, precision, accuracy, robustness, and selectivity for detecting recombinant HPV16-L1 and HPV18-L1 proteins. The nanosensor remained stable for at least 90 days when stored at 4 °C. Clinical evaluation of 173 patients, obtained from cervical samples, showed high specificity (77.8 % for HPV16 and 87.3 % for HPV18) and excellent negative predictive value (>96 % for both). Several false-positive results have been associated with other HPV variants or cervical abnormalities. While the sensitivity was limited by the low prevalence of positive samples, the simple, rapid, and equipment-free nature of this colorimetric nanosensor makes it a promising tool for HPV screening, especially in resource-limited settings.