Food & Biological Engineering, Jiangsu University, China.
Food & Biological Engineering, Jiangsu University, China.
Biosens Bioelectron. 2022 Oct 15;214:114546. doi: 10.1016/j.bios.2022.114546. Epub 2022 Jul 7.
Immunosensor is a promising tool for natural parathion-methyl (PTM) detection, and its analytical advantages can be magnified by introducing flexibly-fabricating technique. Herein, we present a dual-electric-field PTM immunosensor on highly-compatible screen-printed electrode (SPE). MXene-Au, the product of in-situ gold nanoparticle growth on MXene, provides considerable binding sites for PTM antigen (ATG) and methylene blue (MB). During sensing, the MXene-Au-MB-ATG probe competitively binds antibody against PTM, composing a ratiometric immune-system. With DC-biased sine excitations from complementary waveforms, on-chip electric field couple improves immunoreactions among PTM, probe, and antibody. Electric field distribution is programmed by trimming bypass resistors to pursue optimal performance. Probe synthesis is solidly proven with morphological examinations, and competition mechanism between the probe and target PTM is clarified in electrochemical analyses. Remarkably, this method brings less consumption of immune time than electric-field-free or solo-electric-field setup (50 s vs. 900 or 70 s), and simultaneously provides more powerful ratiometric signal than the rivals. Log-linear relationship, between PTM level and sensor readout, is established in 0.02-38 ng/mL, and limit of detection is found as 0.01 ng/mL. This method is applied in laboratorial and natural PTM analyses, and the readouts are consistent with high performance liquid chromatography and recovery test.
免疫传感器是一种很有前途的天然对硫磷-甲基（PTM）检测工具，通过引入灵活的制造技术，可以放大其分析优势。在此，我们在高度兼容的丝网印刷电极（SPE）上展示了一种双电场 PTM 免疫传感器。MXene-Au 是 MXene 原位生长金纳米颗粒的产物，为 PTM 抗原（ATG）和亚甲蓝（MB）提供了大量的结合位点。在传感过程中，MXene-Au-MB-ATG 探针与针对 PTM 的抗体竞争结合，构成了比率免疫体系。通过互补波形的直流偏置正弦激励，片上电场耦合提高了 PTM、探针和抗体之间的免疫反应。通过修剪旁路电阻器来编程电场分布，以追求最佳性能。探针的合成通过形态学检查得到了充分的证实，并且在电化学分析中阐明了探针和目标 PTM 之间的竞争机制。值得注意的是，与无电场或单独电场设置相比，这种方法消耗的免疫时间更少（50s 对 900s 或 70s），并且比竞争对手提供更强大的比率信号。在 0.02-38ng/mL 范围内建立了 PTM 水平和传感器读数之间的对数线性关系，检测限为 0.01ng/mL。该方法应用于实验室和天然 PTM 分析，并且读出结果与高效液相色谱和回收率测试一致。
