Active plasmonic colorimetric biosensor for detecting lung cancer proteins

This study develops an Active Plasmonic Colorimetric (APC) detection chip for quantitative biomolecule detection by observing the dispersion spectrum of plasmons. The active plasmonic detection chip can be applied in Point-of-Care (POC) testing, enabling rapid and convenient diagnostics at the patient’s location. The biosensor integration includes an OLED and a Au nano-grating, The OLED provides stable illumination as a uniform light source. The nano-grating, fabricated using nanoimprint technology is used to excite Surface Plasmon Resonance (SPR). The experimental results show that when the grating period is set to 555nm, the coupling wavelength of the surface plasmon wave exhibits a significant shift in environments with different refractive indices. When the refractive index changes from 1 to 1.33, the coupling wavelength shifts by approximately 190nm. The results indicate that this approach can be used for biomolecule detection. Through wavelength shifts induced by changes in the environmental refractive index, enabling high-sensitivity measurement of biomolecule concentrations. This sensor is expected to be further developed for the detection of Neuron-Specific Enolase (NSE) as a biomarker for lung cancer. Lung cancer is the leading cause of cancer death worldwide, posing a serious threat to life and the economy. The sensor demonstrated a broad linear detection range from 1 ng/mL to 100 ng/mL, with a low detection limit of 200 pg/mL for NSE, as well as excellent selectivity against potential interferences. Future clinical serum matrix analysis will further validate the platform's suitability for sensitive and accurate NSE quantification at clinically relevant levels.