Research Progress on Colorimetric Sensing Based on Optical and Catalytic Properties of Gold Nanoparticles

Colorimetric sensing has shown significant application potentials in the field of point-of-care testing (POCT) due to its advantages of operational simplicity, low cost, fast response time, and easily interpretable signals. Gold nanoparticles (AuNPs) are a key material for constructing high-performance colorimetric sensors due to their unique optical properties, excellent catalytic activity, and highly tunable surface chemistry. However, in practical POCT applications, the stability, sensitivity, and selectivity of AuNP-based colorimetric sensing are still limited by the factors such as complex samples and low target concentration. Therefore, effectively leveraging the inherent properties of AuNPs to enhance sensing performance and overcome challenges in real detection environments has become a crucial research focus. This paper systematically elaborated on the structure-property relationship between the optical and catalytic properties of AuNPs and their structures. It provided an overview of the developed colorimetric sensing strategies and performance enhancement strategies, and proposed feasible strategies and future directions to address existing bottlenecks in practical applications, aiming to provide insights for designing novel sensing modalities tailored to POCT requirements.