SPR biosensing: Cancer diagnosis and biomarkers quantification

Cancer is a leading cause of mortality and morbidity globally, with an estimated 10 million cancer-related fatalities and 19 million new cases in 2020 alone. Despite remarkable advancements in cancer diagnosis and treatment, cancer continues to pose a significant public health challenge. Early and accurate identification is a critical approach for substantially minimizing the risk of mortality and thereby improving prognosis. Traditional methods of diagnosis include physical examination, medical history assessment, and imaging, and frequently necessitate biopsy for verification. However, in recent years, the field has witnessed growing enthusiasm for liquid biopsy and biomarker detection due to their minimally invasive nature, presenting an attractive alternative to traditional biopsy methods. These techniques offer the potential to diagnose, predict, and monitor disease status, contributing to a paradigm shift in cancer diagnostics. The SPR biosensing approach testifies to a great potential for quantifying cancer biomarkers and its implementations go beyond the limits of this review. It is a promising tool, providing great analytical information concerning elevated sensitivity, rapid response, limit of detection, and reproducibility using its label-free and real-time method. This review highlights how SPR can be exploited in the field of cancer including breast, lung, colorectal, and prostate cancer, paving its way for diagnostics. It can be considered a novel technique replacing all the conventional methods for protein quantification (e.g., Western blotting, ELISA, etc.). Furtherance in the study of SPR biosensors is carried out by the use of aptamers, antibodies, and nanoparticles improving its sensitivity and throughput. However, the utility of SPR biosensors is still not yet close to healthcare applications on a large scale and is yet to be worked on and explored. Continuous and significant initiatives are persistently underway to overcome fundamental constraints, and various technological developments like LSPR and SPRi are coming to the forefront. The recent advancement in the SPR biosensing approach may indeed be a better alternative than the present-day screening methods, providing comprehensive information on the structure–function relationships and biomolecular interactions.