Optical biosensing systems for a biological living body

Abstract

With the development of technology, biosensors are increasingly used in the biomedical field. Due to the high sensitivity of optical signals, good stability, high signal‐to‐noise ratio, and different spectral characteristics of different analytes, optical biosensors can achieve direct and real‐time detection of analytes with high specificity compared with traditional analytical techniques. In view of the rapid development of optical biosensors for in vivo applications and their promising future, we have attempted to summarize the working principles and recent advances in application in humans, with the aim of helping readers to gain an in‐depth and detailed understanding of optical biosensors developed in recent years for applications in the biological living body. In this review, we focus on some of the current widely used and promising optical biosensors, including colorimetric biosensors, fluorescence biosensors, and surface‐enhanced‐Raman‐scattering‐based biosensors. The working principles for each type of optical biosensor are concisely described and the application of the biosensor in the living body is summarized by category. We conclude by looking at the prospects of in vivo applications of optical biosensors.

Azobenzene‐Based Conjugated Polymers: Synthesis, Properties, and Biological Applications

“…Light can be precisely manipulated with high spatial and temporal accuracy, prompting researchers to extensively explore various photoresponsive compounds for applications in life sciences research. [ 41 ] Among these, azobenzene is one of the most popular and reliable photoisomerizing molecular functional group. Azobenzene derivatives undergo a clean photoisomerization reaction when irradiated with UV light at 340 nm, converting the stable rod‐like trans‐ isomer into the globular, metastable cis isomer, and vice versa.…”

MicroRNA Biosensors for Early Detection of Hepatocellular Carcinoma

“…Optical signals are insensitive to noise interference, have good stability, and the spectral properties of different molecules to be tested are differentiated with high specificity. Therefore, optical biosensors can directly detect the molecules to be detected [65]. In addition, optical biosensors are easily miniaturized and have the potential to facilitate chip-level integration [66].…”

“…Colorimetric biosensors have the advantages of naked eye determination, low cost, fast response, and ease of fabrication [68]. Colorimetric biosensors can change color in response to external physical or chemical factors, as well as through an enzyme-catalyzed chromogenic reaction inside the sensor, or with the help of metallic nanomaterials [65].…”

Neuromodulatory Compensation of Cortical Neural Activity on Electrodeposited Pt/Ir Modified Microelectrode Arrays for Temperature Transients

“…Here, we fabricated a brain-on-a-chip platform integrating cortical networks and 60-channel electrodeposited platinum/iridium (Pt/Ir) modified MEAs with triple chambers. The application of nanomaterials in the modification of biosensors has become ubiquitous, , enhancing electrochemical performance through organic nanoparticles including nanozymes and conductive polymers , as well as inorganic nanoparticles such as metallic, semiconducting, and carbon-based nanoparticles . The formation of nanocomposites facilitates synergistic interactions among different nanomaterials, which enhances charge transfer kinetics, modulates surface reactivity, and optimizes electron distribution. , Pt/Ir nanocomposites, in particular, are favored in brain–computer interfaces due to their exceptional biocompatibility and stability .…”