Amalesh Nanda, M.Pharm., Thangapandi K., M.Sc., Priyanka Banerjee, Ph.D., Mainak Dutta, Ph.D., Tsering Wangdi, M.D., Pramod Sharma, M.D., Koel Chaudhury, Ph.D., and Saikat Kumar Jana, Ph.D.. Ann Lab Med 2020;40:390-7. https://doi.org/10.3343/alm.2020.40.5.390

Cervical cancer (CC), a significant contributor to the mortality of females globally, manifests an annual incidence of 500,000 cases and is predominantly linked to the human papillomavirus (HPV) infection. The pressing demand for affordable and user-friendly assays for CC detection is highlighted by the limited availability and dependability of diagnostic screening tools, especially in developing countries. In response to the critical need for enhanced cervical cancer diagnostics, we present an innovative electrochemical immunosensor designed for the selective detection of the HPV 16-E7 oncoprotein. The immunosensing platform is constructed from a gold-graphitic carbon nitride (Au-g-C₃N₄) nanocomposite, with antibodies immobilized through a physical adsorption process onto the sensing platform. Employing Square Wave Voltammetry (SWV), we systematically evaluated the antigen-antibody interaction, achieving ultrasensitive detection of E7 with ferric/ferrocyanide. The linear detection range of the proposed sensor for E7 antigen is 0.01 fg ml⁻¹ to 1 ng ml⁻¹, assuming ideal conditions and an impressive Limit of Detection (LOD) of 0.0065 fg ml⁻¹. The accuracy of the proposed immunosensor was effectively evaluated in contrast to Enzyme linked immunosorbent assay (ELISA). Finally, the proposed immunosensor exhibited favourable selectivity, sensitivity, and reproducibility upon introduction to clinical samples, thereby validating its potential suitability for point-of-care testing aimed at the timely detection of CC.

Cervical cancer remains a critical women health issue, predominantly driven by high-risk human papillomavirus (HPV) types, particularly HPV 16 and HPV 18. Late-stage diagnosis, often due to limited diagnostic tools and awareness, exacerbates the problem, especially in developing countries. Addressing these challenges, our study introduces an electrochemical sensor for the detection of HPV18 L1 protein for the first time. The sensor employs gold graphitic carbon nitride (Au-g-C₃N₄) nanocomposite platform with monoclonal antibodies immobilised via a drop-casting method. Detection of the HPV18 L1 protein is achieved using square wave voltammetry. The proposed immunosensor demonstrates a linear detection range (100 ag ml⁻¹ to 1 ngml⁻¹) for L1 protein with a low detection limit (35.16 ag ml⁻¹), and exhibits exceptional sensitivity, selectivity, reproducibility, and stability. Ultimately, this system has been effectively utilised for the identification of L1 in various positive and negative undiluted serum samples and was compared to ELISA for accuracy. The result showed that our electrochemical immunosensor is a promising tool for the reliable, rapid, and accessible detection of HPV18 L1, potentially enhancing cervical cancer diagnostics in clinical settings.