October 10, 2024
Journal Article
Single-Atomic Site Catalyst Enhanced Lateral flow Immunoassay for Point-of-care Detection of Herbicide
Abstract
Point-of-care (POC) detection of herbicide is of great importance due to its impact on the environment and potential risks to human health. Here, a single-atomic site catalyst (SASC) with excellent heme enzyme-like catalytic activity is designed, which enhances the detection performance of corresponding lateral-flow immunoassay (LFIA). The single-atomic site iron catalyst (Fe-SASC) is synthesized from hemin-doped ZIF-8, creating active sites that mimic the Fe active center coordination environment of heme enzyme and their functions. Due to its atomically dispersed iron active sites that result in maximum utilization of active metal atoms, the Fe-SASC exhibits superior heme enzyme-like activity, which has great potential to replace its natural counterparts. The catalytic mechanism of Fe-SASC is systematically investigated. Utilizing its outstanding catalytic activity, the Fe-SASC is used as the label to construct LFIA (Fe-SASC-LFIA) for herbicide detection. The 2,4-Dichlorophenoxyacetic acid (2,4-D) is selected as a target here since it is a commonly used herbicide as well as a biomarker for herbicide exposure evaluation. A linear detection range of 1-250 ng/mL with a low limit of detection (LOD) of 0.82 ng/mL is achieved. Meanwhile, excellent specificity and selectivity towards 2,4-D are achieved. The outstanding detection performance of the Fe-SASC-LFIA is also demonstrated in the detection of human urine samples, indicating the practicability of this POC detection platform for analyzing 2,4-D exposure level of a person. We believe this proposed Fe-SASC-LFIA has remarkable potential as a portable, rapid, and high-sensitive POC detection strategy for pesticide exposure evaluation.Published: October 10, 2024