Dual-mode colorimetric-SPR immunosensor based on gold nanoparticles for sCD146 detection in plasma.

Soluble cluster of differentiation 146 (sCD146) is expressed in various immune cells and plays crucial roles in cellular processes linked to tumor cell metastasis, as well as in cell signalling, migration, proliferation, and inflammation. Detecting sCD146 in plasma has become a promising approach for early cancer screening. A rapid and highly specific dual-mode immunosensor that integrates colorimetry and surface plasmon resonance (SPR) techniques was successfully developed in this study. Specifically, bovine serum albumin (BSA)-modified gold nanoparticles (AuNPs) with exceptional peroxidase (POD) activity and SPR properties were synthesized. Under optimum conditions, the linear range of the immunosensors for sCD146 detection was 5-600 ng/mL. The detection limits (LODs) were 4 ng/mL (colorimetric) and 1 ng/mL (SPR). In addition, the results of this colorimetric and SPR dual-mode immunosensor were essentially consistent with those of the conventional ELISA method (P > 0.05). This dual-mode immunosensor based on AuNPs not only has significant potential for detecting sCD146 in plasma but also offers a versatile and efficient platform for blood biomarker analysis. This novel technology opens new avenues for diagnosing cancer and predicting cancer prognosis, thereby having substantial implications for both scientific research and clinical applications.