International Joint Research Center for Photoresponsive Molecules and Materials, Jiangnan University, Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, Jiangnan University, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China.
International Joint Research Center for Photoresponsive Molecules and Materials, Jiangnan University, Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, Jiangnan University, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China.
Anal Chim Acta. 2019 Jun 13;1058:1-8. doi: 10.1016/j.aca.2019.01.057. Epub 2019 Feb 10.
Most of the photoelectrochemical (PEC) bioassays need to immobilize biomolecules on electrodes, which lead to tedious modification processes, damaged biomolecules, as well as crippled sensitivity/accuracy and low throughput of the performances. To overcome these drawbacks, we now introduce an exquisitely split-mode (which separates the bioreaction (performed in microplates) from the PEC detection (conducted in PEC cell)) cathodic photoelectrochemistry for probing versatile biocatalytic events with high throughput. Specifically, the enzymatically in situ generated 1,2-bezoquinone was covalently attached onto the PbSe quantum dots (QDs) modified indium tin oxide (ITO) (ITO/PbSe) photocathode through the connector of chitosan (CS). And the attached 1,2-bezoquinone acted as an efficient electron acceptor to promote the cathodic photocurrent of the ITO/PbSe electrode, enabling us to probe quinones-generating oxidoreductase (by taking horseradish peroxidase (HRP) as a model) coupled biocatalytic cascades including the alkaline phosphatase (ALP)/HRP and the glucose oxidase (GOx)/HRP cascades. Quantitative probing for ALP activity in a wide linear range of 5.0 × 10 to 10 U/L with the detection limit of 1.2 × 10 U/L was realized. While a wide linear range of 5.0 × 10 to 1.0 × 10 moL/L with a quite low detection limit of 1.0 × 10 moL/L was obtained for the glucose assay. In addition, this testing protocol was also extended to an immunoassay (taking carcinoembryonic antigen (CEA) as an example) using HRP as a catalytic tracer. The developed bioassays show high sensitivity and good selectivity for CEA detection in the linear range from 0.1 pg/mL to 100 ng/mL with a detection limit of 0.02 pg/mL. Moreover, the proposed detection has distinctive merits because it not only avoids the adverse effects of the surface confined biomolecules for crippling the signal transduction, but also it has enhanced throughput.
大多数光电化学 (PEC) 生物测定需要将生物分子固定在电极上，这导致繁琐的修饰过程、生物分子的损伤，以及性能的灵敏度/准确性降低和通量降低。为了克服这些缺点，我们现在引入了一种精致的分裂模式（将生物反应（在微板中进行）与 PEC 检测（在 PEC 电池中进行）分开）用于探测具有高通量的多功能生物催化事件的阴极光电化学。具体来说，通过壳聚糖（CS）的连接器，在原位生成的 1,2-苯醌被共价连接到 PbSe 量子点 (QDs) 修饰的氧化铟锡 (ITO) (ITO/PbSe) 光电阴极上。附着的 1,2-苯醌充当有效的电子受体，以促进 ITO/PbSe 电极的阴极光电流，使我们能够探测产生醌的氧化还原酶（以辣根过氧化物酶 (HRP) 为模型）偶联的生物催化级联，包括碱性磷酸酶 (ALP)/HRP 和葡萄糖氧化酶 (GOx)/HRP 级联。实现了在 5.0×10 至 10 U/L 的宽线性范围内对 ALP 活性的定量探测，检测限为 1.2×10 U/L。同时，对于葡萄糖测定，获得了 5.0×10 至 1.0×10 mol/L 的宽线性范围和 1.0×10 mol/L 的相当低的检测限。此外，该测试方案还扩展到使用 HRP 作为催化示踪剂的免疫测定（以癌胚抗原 (CEA) 为例）。开发的生物测定法在 0.1 pg/mL 至 100 ng/mL 的线性范围内对 CEA 检测具有高灵敏度和良好的选择性，检测限为 0.02 pg/mL。此外，该检测具有独特的优点，因为它不仅避免了表面限制的生物分子对信号转导造成的不利影响，而且还提高了通量。
