Abstract
<jats:p>Optical sensors for virus detection are an emerging technology used to identify viral particles or their markers in a sample. Detection of viruses is crucial for diagnosing infections in humans, animals, and plants, and for identifying viruses in environmental samples. Depending on the virus type, infection stage, and available resources, different methods such as polymerase chain reaction, enzyme-linked immunosorbent assay, next-generation sequencing, microscopy, clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostics, and optical sensors are used to detect viruses. In recent years, there has been significant interest in rapid, non-invasive testing using optical sensors to detect viruses quickly in diverse environments. Research is ongoing to increase the sensitivity, portability, and usability of optical sensors. Optical sensors often utilise light, optics, and, sometimes, nanomaterials to detect the presence of viruses quickly and with high sensitivity. In this chapter, the working principles of optical sensors are explained and recent studies on virus detection across various applications are thoroughly reviewed.</jats:p>