局域表面等离激元共振在单分子灵敏度检测中的应用及进展

Localized surface plasmon resonance (LSPR) is a unique optical property of noble-metal nanomaterials, such as gold and silver, which can be used to achieve increasingly more applications in human health due to its sensitivity to changes in the refractive index and others of the surrounding environment and has therefore attracted wide attention from researchers. In addition to this, the single molecule is the smallest unit to be studied in the process of life activity, and the study of it presents a challenge to the limit of detection technology. Therefore, the combination of LSPR with the detection strategies of single-molecule recognition can provide a good system for studying the interaction between light and matter at the molecular level, which has extraordinary scientific significance and value for the study of intermolecular affinity, molecular dynamics, and pharmacokinetics, etc. Based on the above background, starting from the LSPR sensing strategies, we first introduce its basic principle and explain the factors affecting the sensing performance, and then discuss the design scheme of highly sensitive optical sensing technology, which can be controlled by the materials, geometric shape and surrounding environment of metal nanoparticles to promote the generation of hot spots, the regulation of their distribution and density, and the enhancement of the electromagnetic field intensity. More refined optical sensing strategies can be devised and optimized for high-sensitivity detection by capitalizing on highly sensitive sensing substrates to magnify the minute variations in the target molecules and ultimately manifest the alterations in the molecular recognition process in the form of optical signals. Finally, the advanced applications of different design schemes in detections with single-molecule sensitivity (DSMS) are analyzed comprehensively, and the development trends of this technology are summarized. Hopefully, this paper can provide new ideas for researchers to develop and design LSPR optical biological or chemical sensors, and effectively optimize and expand the applications of LSPR in DSMS.