State Key Laboratory of Photocatalysis on Energy and Environment, Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & MOE), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
State Key Laboratory of Photocatalysis on Energy and Environment, Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & MOE), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
Biosens Bioelectron. 2017 Mar 15;89(Pt 1):645-651. doi: 10.1016/j.bios.2015.12.035. Epub 2015 Dec 21.
A new colorimetric immunosensing platform accompanying enzyme cascade amplification strategy was fabricated for quantitative screening of small-molecular mycotoxins (aflatoxin B, AFB used in this case) coupling with enzyme-controlled dissolution of MnO nanoflakes. The visual colored assay was executed by high-efficient MnO-3,3',5,5'-tetramethylbenzidine (TMB) system (blue). In the presence of ascorbic acid, MnO nanoflakes were dissolved into Mn ions, thus resulting in a perceptible color change from blue to colorless. The reaction could be weakened through ascorbate oxidase to catalyze ascorbic acid into dehydroascorbic acid, which indirectly depended on the concentration of ascorbate oxidase. By using ascorbate oxidase/ anti-AFB antibody-labeled gold nanoparticles, a novel competitive-type colorimetric enzyme immunoassay was developed for detection of AFB on AFB-bovine serum albumin (BSA)-conjugated magnetic beads. Upon addition of target AFB, the analyte competed with the conjugated AFB-BSA on the magnetic beads for the labeled anti-AFB antibody on the gold nanoparticles. Under optimal conditions, the absorbance decreased with increasing target AFB within the dynamic range of 0.05-150ngmL with a detection limit of 6.5pgmL at the 3S level. The precision and specificity of the MnO-TMB-based immunosensing system were acceptable. In addition, method accuracy was further validated for monitoring spiked peanut samples, giving results matched well with those obtained from commercialized AFB ELISA kit.
一种新的比色免疫传感平台，结合酶级联扩增策略，用于定量筛选小分子真菌毒素（此处使用黄曲霉毒素 B，AFB），同时结合酶控制 MnO 纳米薄片的溶解。通过高效的 MnO-3,3',5,5'-四甲基联苯胺（TMB）系统（蓝色）执行可视化比色测定。在抗坏血酸存在下，MnO 纳米薄片溶解成 Mn 离子，从而导致从蓝色到无色的明显颜色变化。该反应可以通过抗坏血酸氧化酶减弱，以催化抗坏血酸转化为脱氢抗坏血酸，这间接取决于抗坏血酸氧化酶的浓度。通过使用抗坏血酸氧化酶/抗 AFB 抗体标记的金纳米粒子，开发了一种新型的竞争性比色酶免疫测定法，用于检测 AFB-BSA 偶联磁珠上的 AFB。加入目标 AFB 后，分析物与偶联 AFB-BSA 在磁珠上竞争，以获取金纳米粒子上标记的抗 AFB 抗体。在最佳条件下，吸光度随目标 AFB 的增加而降低，在 0.05-150ngmL 的动态范围内，检测限为 6.5pgmL（3S 水平）。MnO-TMB 基于的免疫传感系统的精度和特异性是可以接受的。此外，进一步通过对加标花生样品进行方法准确性验证，得到的结果与商业化 AFB ELISA 试剂盒的结果吻合良好。
