A novel colorimetric immunosensor based on silk cocoon membrane-integrated ELISA for treponemal antibody detection

作者：Hongmei Wang, Yizhi Huang, Qi Xiao, Yezhou Chen, Yujue Wang, Jingjing Tian, Yuqing Cai, Longhai Tang, Shaohua Ding, Shengbao Duan · 发表于：Microbiology Spectrum · 年份：2025 · DOI：10.1128/spectrum.00094-25 · 被引用次数：2 · 研究领域：Advanced biosensing and bioanalysis techniques、Virology and Viral Diseases、Syphilis Diagnosis and Treatment

ABSTRACT The global rise in syphilis incidence and the challenges of early diagnosis highlight the urgent need for convenient diagnostic tools. In this study, we present a colorimetric immunosensor for the detection of Treponema pallidum antibodies (TP-Ab) using a natural silk cocoon membrane (SCM) as the substrate, based on the principle of enzyme-linked immunosorbent assay (ELISA). The TP monoclonal antibody 3H12 and the chimera antigen TP99, comprising epitopes TP15, TP17, and TP47, were sequentially coupled to functionalized SCM to form the SCM-based TP-Ab immunosensor. The detection was quantified by color extraction, and the Corrected I red values were used as a judgment parameter. The TP-Ab immunosensor demonstrated a detection limit of 0.48 mIU/mL, lower than the 0.68 mIU/mL limit of commercial microplate ELISA kits. Furthermore, it exhibited no cross-reactivity with antibodies against other pathogens. Testing with a reference serum panel yielded 100% concordance with the reference results. Comprehensive statistical analysis of the Corrected I red values from the reference serum panel and banked samples indicated an optimal cutoff value of 0.0921, achieving 100% sensitivity, 97.96% specificity, and high overall accuracy, with an area under the curve of 0.9995 and a 95% confidence interval of 0.9979–1.00. Moreover, a statistically significant correlation with microplate ELISA was observed ( r = 0.9217, P < 0.0001). This reliable ELISA-integrated colorimetric immunos...