Chromogenic Mechanisms of Colorimetric Sensors Based on Gold Nanoparticles

Abstract

The colorimetric signal readout method is widely used in visualized analyses for its advantages, including visualization of test results, simple and fast operations, low detection cost and fast response time. Gold nanoparticles (Au NPs), which not only exhibit enzyme-like activity but also have the advantages of tunable localized surface plasmon resonance (LSPR), high stability, good biocompatibility and easily modified properties, provide excellent platforms for the construction of colorimetric sensors. They are widely used in environmental monitoring, biomedicine, the food industry and other fields. This review focuses on the chromogenic mechanisms of colorimetric sensors based on Au NPs adopting two different sensing strategies and summarizes significant advances in Au NP-based colorimetric sensing with enzyme-like activity and tunable LSPR characteristics. In addition, the sensing strategies based on the LSPR properties of Au NPs are classified into four modulation methods: aggregation, surface modification, deposition and etching, and the current status of visual detection of various analytes is discussed. Finally, the review further discusses the limitations of current Au NP-based detection strategies and the promising prospects of Au NPs as colorimetric sensors, guiding the design of novel colorimetric sensors.

Construction of a three-mode sensor based on gold nanoparticles and carbon quantum dots as probes for the detection of thiosemicarbazone

“…29,30 According to the change in SPR peak and color, colorimetric and chrominance sensors can be constructed, respectively, to detect target analytes. 31,32 Alternatively, as energy acceptors, AuNPs and other precious metal nanoparticles can undergo resonance energy transfer (FRET) with FL donors to quench FL. 33,34 However, the FRET effect reduces and partial recovery of FL occurs when gold nanoparticles aggregate.…”

“…29,30 According to the change in SPR peak and color, colorimetric and chrominance sensors can be constructed, respectively, to detect target analytes. 31,32…”

Sialic Acid-Functionalized Gold Nanoparticles for Sensitive and Selective Colorimetric Determination of Serotonin

“…By engineering the interaction between the nanoparticles’ surface and the analyte, a color shift can be generated. This shift, which is often mediated by electrostatic forces, hydrogen bonds, or even chemical reactions, allows for the visual detection of the analyte. − Detection methods developed in recent years based on the LSPR phenomenon are very sensitive and can be used in the determination of different analytes like pesticides, amino acids, cancer cells, and metabolites …”