Colorimetric visualization detection of perfluorooctanoic acid based on host–guest interactions with cyclodextrin-modified gold nanoparticles

Abstract

Perfluorooctanoic acid (PFOA) is a pervasive environmental contaminant known for its resistance to degradation and its tendency to bioaccumulate in living organisms. Due to its persistent and harmful nature, the development of fast, sensitive detection methods is critical for effective environmental monitoring and safeguarding public health. This study developed a colorimetric sensor based on the host–guest interactions between PFOA and cyclodextrin-modified gold nanoparticles (CD@AuNPs) for the visual detection of PFOA. The interaction between cyclodextrin and PFOA induced aggregation of the gold nanoparticles, leading to a visible color change in the solution from red to blue-purple, enabling the visual detection of PFOA. Experimental results demonstrated that the sensor offered satisfactory sensitivity for detection of PFOA, with a detection limit of 170 nM, 156 nM, and 204 nM using α-CD@AuNPs, β-CD@AuNPs and γ-CD@AuNPs respectively. Notably, it maintained selective recognition of PFOA in the presence of other perfluorocarboxylic acids. Recovery rates of spiked PFOA in lake water samples ranged from 98% to 129%. With its simplicity, rapid detection, and cost-efficiency, this method is particularly suited for on-site environmental monitoring.