A new photoluminescence (PL) enzyme immunoassay was designed for sensitive detection of aflatoxin B₁ (AFB₁) via an innovative enzyme substrate, 6-aza-2-thiothymine-stabilized gold nanocluster (AAT-AuNC) with L-arginine. The enzyme substrate with strong PL intensity was formed through supramolecular host-guest assembly between guanidine group of L-arginine and AAT capped on the surface of AuNC. Upon arginase introduction, the captured L-arginine was hydrolyzed into ornithine and urea, thus resulting in the decreasing PL intensity. Based on this principle, a novel competitive-type immunoreaction was first carried out on AFB₁-bovine serum albumin (AFB₁-BSA) conjugate-coated microplate, using arginase-labeled anti-AFB₁ antibody as the competitor. Under the optimum conditions, the PL intensity increased with the increment of target AFB₁, and allowed the detection of the analyte at concentrations as low as 3.2 pg mL⁻¹ (ppt). Moreover, L-arginine-AAT-AuNC-based PL enzyme immunoassay afforded good reproducibility and acceptable specificity. In addition, the accuracy of this methodology, referring to commercial AFB₁ ELISA kit, was evaluated to analyze naturally contaminated or spiked peanut samples, giving well-matched results between two methods, thus representing a useful scheme for practical application in quantitative monitoring of mycotoxins in foodstuff.

设计了一种新的光致发光（PL）酶免疫测定法，用于通过创新的酶底物，带有L-精氨酸的6-氮杂-2-硫代胸腺嘧啶稳定的金纳米簇（AAT-AuNC）灵敏检测黄曲霉毒素B ₁（AFB ₁）。通过L-精氨酸的胍基和AuNC表面封端的AAT之间的超分子宿主-客体组装形成具有强PL强度的酶底物。引入精氨酸酶后，捕获的L-精氨酸被水解为鸟氨酸和尿素，从而导致PL强度降低。基于此原理，首先对AFB _1-牛血清白蛋白（AFB）进行了新的竞争型免疫反应。使用精氨酸酶标记的抗AFB ₁抗体作为竞争剂，使用₁ -BSA）偶联物包被的微孔板。在最佳条件下，PL强度随目标AFB _1的增加而增加，并允许以低至3.2 pg mL ^-1（ppt）的浓度检测分析物。而且，基于L-精氨酸-AAT-AuNC的PL酶免疫测定提供了良好的再现性和可接受的特异性。此外，此方法的准确性，指的是商用AFB ₁ 对ELISA试剂盒进行了评估，以分析自然污染或加标的花生样品，从而在两种方法之间得到了很好的匹配结果，从而代表了一种在食品中真菌毒素定量监测中实际应用的有用方案。