FIBRE OPTIC IMMUNOSENSORS: A NOVEL APPROACH TO IDENTIFY CANCER BIOMARKERS

Abstract

Cancer is still one of the most significant worldwide health risks, and one of the reasons why is the imperative need for cutting-edge diagnostic technology to enable early, accurate detection. The current research addresses the development of fibre-optic immunosensors with SPR technology for specific detection of ALDH1A1, a biomarker highly associated with cancer stem cells, cancer malignancy, and drug resistance. The work focuses on optimizing the sensor's analytical performance using advanced functionalization methods and thorough spectral characterization, with the goal of creating a reliable tool for clinical cancer diagnosis. The experimental protocol involved the fabrication of SPR sensors, which were subsequently functionalized with ALDH1A1 specific antibodies utilizing protein G in order to preserve the proper antibody orientation. Comprehensive calibration using sucrose solutions over a range of concentrations was employed to calibrate the sensors' refractive index sensitivity. Detection capabilities were evaluated systematically through exposure to ALDH1A1 protein concentrations between 10 femtomolar and 100 nanomolar. The results showed significant differences in sensor response properties, with some sensors exhibiting high reproducibility and stability and others showing more unpredictable performance, suggesting the influence of functionalization quality and experimental conditions. The findings of this research indicate the great potential of SPR-based fibre-optic biosensors as a very sensitive and convenient platform for cancer biomarker detection. The capability of the technology to attain low detection limits with specificity is a key strength over other conventional diagnostic tools. Future research directions include the development of multiplexed detection systems and full clinical validation studies to bring this technology more towards practical realization in the medical setting, the potential to change early cancer detection and patient monitoring.