Differential Measurement of a Compact LSPR Biosensor System by Two Filter-Free Wavelength Sensors for Improved Molecular Selectivity

• Main Authors: Sakae, Tsugumi, Choi, Yong-Joon, Ide, Tomoya, Takahashi, Kazuhiro, Noda, Toshihiko, Sawada, Kazuaki
• Format: Conference Proceeding
• Language: English
• Subjects: compact; Coronaviruses; filter-free; localized surface plasmon resonance; Proteins; SARS-CoV-2; Semiconductor device measurement; Sensitivity; Sensor systems; Sensors; Spike Protein; virus detection system; Wavelength measurement; wavelength sensor
• ISSN: 2168-9229
• DOI: 10.1109/SENSORS56945.2023.10325233

In this paper, to selectively and sensitively detect target molecules, we proposed a differential measurement method using two arrayed filter-free wavelength sensors, which was demonstrated by detecting the SARS-CoV-2 Spike S1 protein. A nanohole-structured LSPR chip with an area of 80 \mu\mathrm{m} was fabricated and confirmed a high correlation between the FDTD simulation and measurement results of transmitted spectra. Also, we optimized the wavelength of LED light sources to detect spectral shifts with high sensitivity due to molecular adsorption. Comparing the current ratio of the sensor by each light source, the current ratio difference between the xenon light source and LED (625 nm) was 0.017 and 0.102, which is about six times the sensitivity. Furthermore, two arrayed filter-free wavelength sensors can remove wavelength changes due to non-specific adsorption by molecules other than the detection target. These results verify that the proposed multi-measurement method using a filter-free wavelength sensor can selectively detect only specimen molecules. Therefore, we expect the proposed compact LSPR system to detect target molecules with high sensitivity and selectivity.