Laser-induced Fluorescence Detection of Cold-induced RNA Binding Protein Based on the Fluorescence Enhancement Effect of Photonic Crystal

Fluorescence immunoassay technology assumes a pivotal role in achieving exceptional sensitivity for disease biomarker detection. In this paper, we proposed a cost-effective and user-friendly fluorescence biosensing method with a low detection limit for the detection of liver cancer. We fabricated fluorescence immunosensors by 300-nm SiO
2
photonic crystal films through vertical deposition. Our method utilized the fluorescence enhancement effect in conjunction with laser-induced fluorescence (LIF) detection technology. Based on the comprehensive analysis of simulation and experimental results, we concluded that the optimal fluorescence enhancement effect of the fabricated film occurs when the incident angle is set to 45°, corresponding to an emission wavelength of 520 nm. The immunosensor exhibited a linear correlation between the fluorescence intensity and the cold-induced RNA binding protein (CIRP) concentration in the range of 0.01 ng/mL to 1000 ng/mL, with a detection limit of 0.01 ng/mL. Moreover, the immunosensor can be tuned to detect other proteins of interest depending on the immobilized antibody.