{Reference Type}: Journal Article
{Title}: Plasmonic enzyme immunoassay via nanobody-driven controllable aggregation of gold nanoparticles for detection of ochratoxin A in pepper.
{Author}: Mao F;He Z;Sun Z;Zhang S;Cao H;Liu X;
{Journal}: Food Chem
{Volume}: 453
{Issue}: 0
{Year}: 2024 Sep 30
{Factor}: 9.231
{DOI}: 10.1016/j.foodchem.2024.139623
{Abstract}: Ochratoxin A (OTA) in food poses a serious challenge to public health. Herein, using the nanobody-driven controllable aggregation of gold nanoparticles (AuNPs) in a glucose oxidase-tyramine-horseradish peroxidase (GOx-TYR-HRP) system, we propose a direct competitive plasmonic enzyme immunoassay (dc-PEIA) for OTA detection. The OTA-GOx conjugate catalyzes glucose to produce hydrogen peroxide (H2O2), and then HRP catalyzes H2O2 to generate hydroxyl radical which induces the crosslink of TYR. Crosslinked TYR leads to aggregation of AuNPs through strong electrostatic interactions, which is tunable based on the competition of OTA-GOx and free OTA for binding the immobilized nanobody. The optimized dc-PEIA achieves an instrumental limit of detection (LOD) of 0.275 ng/mL and a visual LOD of 1.56 ng/mL. It exhibits good selectivity for OTA and accuracy in the analysis of pepper samples, with the confirmation of high-performance liquid chromatography. Overall, the dc-PEIA is demonstrated as a useful tool for detecting OTA in food.