Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China; The Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China.
Anal Chim Acta. 2020 Oct 2;1132:101-109. doi: 10.1016/j.aca.2020.07.068. Epub 2020 Aug 6.
Oxidase nanozymes have attracted particular attention in colorimetric immunoassay due to their high activity, stability, and biocompatibility. In this work, the well-dispersed Co(OH) nanocages were synthesized by a template-assisted strategy. The prepared Co(OH) nanocages exhibited an intrinsic oxidase-like activity, which can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) without the addition of hydrogen peroxide (HO). Hence, a simple and sensitive colorimetric immunoassay was established to detect ochratoxin A (OTA). In this immunosensor, the microplates were modified with dopamine as the substrate to capture antigens. Then, the uniform Co(OH) nanocages were used as the vehicle to carry the secondary antibody for the recognition of immunoreaction. The sensing system can generate color responses with the OTA concentration in the range from 0.5 ng/L to 5 μg/L, and the detection limit was as low as 0.26 ng/L. Therefore, as a nano-artificial enzyme, Co(OH) nanocages may show promising potential in visual detection of the real samples.
氧化酶纳米酶由于其高活性、高稳定性和良好的生物相容性，在比色免疫分析中受到了特别关注。本工作采用模板辅助策略合成了分散良好的 Co(OH)纳米笼。所制备的 Co(OH)纳米笼具有内在的类氧化酶活性，无需添加过氧化氢 (HO) 即可氧化 3,3',5,5'-四甲基联苯胺 (TMB)。因此，建立了一种简单灵敏的比色免疫分析方法来检测赭曲霉毒素 A (OTA)。在该免疫传感器中，微孔板用多巴胺作为基底修饰以捕获抗原。然后，均匀的 Co(OH)纳米笼被用作携带二级抗体的载体，以识别免疫反应。该传感系统可在 OTA 浓度为 0.5ng/L 至 5μg/L 的范围内产生颜色响应，检测限低至 0.26ng/L。因此，作为一种纳米人工酶，Co(OH)纳米笼在实际样品的可视化检测中可能具有广阔的应用前景。
