Subwavelength periodic dielectric nanostructures for biochemical sensing

Beliaev, Leonid; Takayama, Osamu; Laurynenka, Andrei

doi:10.1117/3.100303.ch5

Book: Biophotonics and Biosensing: From Fundamental Research to Clinical Trials Through Advances of Signal and Image Processing

Editor(s): Andrea Armani; Tatevik Chalyan; David D. Sampson

Chapter Author(s): Leonid Beliaev, Osamu Takayama, Andrei Laurynenka

Published: 2024

https://doi.org/10.1117/3.100303.ch5

Abstract

A sensor is an analytical tool that can detect and respond to physical input from its environment and convert it into a measurable optical or electrical signal. A typical sensor has three parts: a recognition element, a transducer, and a signal processing part. Sensors can be used in various fields, such as medicine, environmental monitoring, and biotechnology. Each application has specific requirements for measuring the analyte, including concentration, precision, sample volume, and time required to complete the probing. Sensor devices can be classified into different groups, depending on the signal transduction method: electrochemical, acoustic, optical biosensors, etc. In this chapter, we focus on the latter read-out scheme. Optical sensors measure variations in light properties, such as polarization, intensity, and wavelength, as the reaction on biological or chemical interactions. They can be divided into two categories: label-based and label-free. Label-based optical sensing uses special “labels” to generate an optical signal, whereas label-free sensing generates the signal directly through interactions between the analyzed material and the transducer. Optical sensors offer advantages over other conventional analytical techniques, such as direct detection of substances in real-time, high specificity, sensitivity, small size, and cost-effectiveness. Optical sensor miniaturization allows chip-level integration, and lab-on-a-chip devices can also incorporate other functionalities, such as microfluidics.