Label-free biosensor on chip (BoC) based on localized surface plasmon resonance for monitoring temperature and blood hemoglobin concentration

Abstract

On-chip localized surface plasmon resonance (LSPR) biosensor on chip (BoC) is a type of label-free biosensor that utilizes the plasmonic resonances of metal nanostructures to detect changes in the refractive index of the local environment. This results in changes in the intensity and wavelength of the surface plasmon resonance, which can be used to quantify the presence and concentration of biomolecules such as proteins, nucleic acids, and cells. In this paper, we propose a novel on-chip device with a microfluidic channel that contains the biological fluid under test. We have obtained sharp resonance peaks in the wavelength range between 700–800 nm with a sensitivity of 509 nm R−1IU−1 which is good compared to other on-chip devices. The main advantage of our design is the less complex manufacturing process compared to other BoCs. Our design consists of a central cavity that is surrounded by silver and consists of rectangular pillar-shaped silver particles placed in the cavity. Two very promising applications of this device are label-free temperature sensing and blood hemoglobin (Hb) concentration sensing with a resolution of 0.222 nm/°C for temperature and 1. 34 nm/(g/dL) for Hb. However, it can be used for any kind of sensing application that involves refractive index changes as the sensing platform.