(INVITED)Development of custom Surface Plasmon Resonance Au biosensor for liver cancer biomarker detection

Label-free plasmonic biosensors have demonstrated promising capabilities as diagnostic tools for the detection of different target analytes. The overall analytical sensitivity and specificity of these systems depend on the sensor surface biofunctionalization, since it influences their interactions with the target molecules and determines their applicability to biomolecular detection in complex matrices. In this study, we report the development of Au biosensor by integrating the immunosandwich sensing approach into a Surface Plasmon Resonance (SPR) system for detecting cancer biomarkers at a concentration as low as the picomolar range. Our work has demonstrated that antibody-functionalized sensing film, together with signal amplification by detection antibody, was readily served as a plasmonic partner that can be used as a powerful ultrasensitive sandwich immunoassay for cancer-related disease diagnosis. The proposed Au biosensor is designed with high detection accuracy and sensitivity for alpha-fetoprotein (AFP), a well-known liver cancer biomarker. AFP detection performed by our Au biosensor provides an impressive limit of detection equal to 1.5 ng/ml in a saline buffer, lower than the relevant clinic concentration. The data reported here can contribute to the development of label-free device that can be freely functionalized to obtain an even better recognition of different biomarkers in real-time and with high reproducibility thanks to the possibility of being used after regeneration, offering an effective option for cancer screening suitable in point-of-care (POC) testing.