Aminolated and Thiolated PEG‐Covered Gold Nanoparticles with High Stability and Antiaggregation for Lateral Flow Detection of Bisphenol A

The few lateral flow assays (LFAs) established for detecting the endocrine disrupting chemical bisphenol A (BPA) have employed citrate‐stabilized gold nanoparticles (GNPs), which have inevitable limitations and instability issues. To address these limitations, a more stable and more sensitive biosensor is developed by designing strategies for modifying the surfaces of GNPs with polyethylene glycol and then testing their effectiveness and sensitivity toward BPA in an LFA. Without the application of any enhancement strategy, this modified BPA LFA can achieve a naked‐eye limit of detection (LOD) of 0.8 ng mL−1, which is 12.5 times better than the LOD of regular BPA LFAs, and a quantitative LOD of 0.472 ng mL−1. This modified LFA has the potential to be applied to the detection of various antigens. A more stable and more sensitive biosensor is developed by designing strategies for modifying the surfaces of gold nanoparticles (GNPs) and then testing their effectiveness and sensitivity toward bisphenol A in a lateral flow assay. The modified GNPs were prevented from aggregation during the strip fabrication and testing processes, and the amount of waste arising from failed experiments is significantly reduced.