Zhi Li-Juan, Sun Ai-Li
Department of Chemistry and Chemical Engineering, Xinxiang University, Xinxiang, 453000, PR China.
Department of Chemistry and Chemical Engineering, Xinxiang University, Xinxiang, 453000, PR China; Key Laboratory of Nano-carbon Modified Film Technology Engineering (Henan Province), Department of Pharmacy, Xinxiang University, Xinxiang, 453000, PR China.
Anal Chim Acta. 2020 Oct 16;1134:106-114. doi: 10.1016/j.aca.2020.08.026. Epub 2020 Aug 20.
An innovative electrochemical immunosensing platform was designed for the sensitive monitoring of lung cancer biomarker (pro-gastrin-releasing peptide; ProGRP) by using platinum nanoparticles encapsulated inside dendrimers (PtDEN) as enzymatic mimics for the signal amplification. PtDEN nanocomposites were prepared through a simple chemical reduction method with the assistance of NaBH. Thereafter, PtDEN-labeled anti-ProGRP secondary antibody was launched for the detection of target analyte with a sandwich-type assay format on anti-ProGRP capture antibody-modified screen-printed carbon electrode. Accompanying formation of immunocomplex, the labeled PtDENs electrochemically oxidized 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide to produce a well-defined voltammetric signal within the applied potentials. Thanks to the high-efficient catalytic efficiency of platinum nanoparticles and high-loading ability of dendrimer, improved analytical features were acquired with PtDENs relative to platinum nanoparticles alone. Using PtDENs labeling strategy, the properties and factors influencing the analytical performance of electrochemical immunosensor were studied in detail. The strong bioconjugation of antibodies with the PtDENs caused a good repeatability and intermediate precision down to 7.64%. Under optimum conditions, the electrochemical immunosensor exhibited a dynamic linear range of 0.001-10 ng mL ProGRP with a detection limit of 0.86 pg mL. Good selectivity and relatively long-term stability (>6 months) were achieved for target ProGRP. Significantly, the acceptable accuracy was gotten for analysis of ProGRP in human serum specimens referring to commercially available human ProGRP enzyme-linked immunosorbent assay (ELISA) method.
设计了一种创新的电化学免疫传感平台，通过使用包裹在树枝状大分子内的铂纳米颗粒（PtDEN）作为酶模拟物进行信号放大，用于灵敏监测肺癌生物标志物（胃泌素释放肽前体；ProGRP）。通过在硼氢化钠的辅助下采用简单的化学还原方法制备了PtDEN纳米复合材料。此后，在抗ProGRP捕获抗体修饰的丝网印刷碳电极上，采用夹心型检测模式，利用PtDEN标记的抗ProGRP二抗检测目标分析物。随着免疫复合物的形成，标记的PtDEN在过氧化氢存在下将3,3',5,5'-四甲基联苯胺（TMB）电化学氧化，从而在施加电位范围内产生明确的伏安信号。由于铂纳米颗粒的高效催化效率和树枝状大分子的高负载能力，与单独的铂纳米颗粒相比，PtDEN具有更好的分析特性。采用PtDEN标记策略，详细研究了影响电化学免疫传感器分析性能的性质和因素。抗体与PtDEN的强生物共轭导致良好的重复性和中等精密度，低至7.64%。在最佳条件下，电化学免疫传感器对ProGRP的动态线性范围为0.001 - 10 ng mL，检测限为0.86 pg mL。对目标ProGRP实现了良好的选择性和相对长期的稳定性（>6个月）。值得注意的是，参照市售人ProGRP酶联免疫吸附测定（ELISA）方法，该电化学免疫传感器对人血清样本中ProGRP的分析具有可接受的准确度。
