Plasmonic biosensor for early gastric cancer detection

Abstract

Early detection of cancer, can greatly reduce mortality and thus increase the life expectancy of patients. In this study, we introduce a plasmonic biosensor platform to detect relevant microRNAs for gastric cancer diagnosis. The proposed sensor uses the LSPR to detect RNA in the human blood. Different geometries of nanostructures were examined, and the results of their resonance peak were analyzed. The proposed nano-flower structure with five petals was considered as the original shape and then was examined in terms of changes, including substrate changes, the type of structure, the presence or absence of holes on the structure, and different thicknesses of the desired biomarkers. It shows the optimal wavelength of LSPR at 652 nm, which is suitable for physiological environments such as blood and plasma. The creation of several holes caused a shift to the wavelength of 663.63 nm, which was about 12.12 nm, but due to the reduction of the peak intensity, the optimization steps were performed without holes. Target miRNAs such as miR-21, miR-221, and miR-153 are selectively trapped on nanostructured surfaces and change λ LSPR . The resonance peak of the LSPR found a 30 nm shift due to the presence of biomarkers.