Chen Kexuan, Ma Nan, Sun Haobo, Zhang Xueji, Kong Jinming
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, P. R. China.
School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, Guangdong 518060, P. R. China.
Analyst. 2023 Mar 27;148(7):1587-1594. doi: 10.1039/d3an00213f.
Preeclampsia (PE) seriously affects pregnant women and fetuses' health and causes maternal near-misses. CD81 has been confirmed to be a novel PE biomarker with great potential. Herein, a hypersensitive dichromatic biosensor based on the plasmonic enzyme-linked immunosorbent assay (plasmonic ELISA) is proposed initially for the application of CD81 in early screening for PE. In this work, a novel chromogenic substrate [(HAuCl)-(-methylpyrrolidone)-(NaCHO)] is designed based on the HO dual catalysis reduction pathway of Au ions. The two reduction pathways of Au ions are controlled by HO which ensures that the synthesis and growth of AuNPs are sensitive to HO. The amount of HO correlates with the concentration of CD81 and directs the production of different-sized AuNPs in this sensor. Blue solutions are generated when analytes are present. When analytes are absent, solutions turn red. Therefore, due to different absorption peaks in red and blue, bimodal detection can be performed, and then two detection signals can be generated, one on signal at 550 nm and another off signal at 600 nm. This method exhibits a linear response to the logarithmic CD81 concentrations in the range of 0.1-1000 pg mL with detection limits of 86 fg mL and 152 fg mL at two wavelengths. The false positive rate is low due to the nonspecific coloration caused by serum, which produces a more intense color contrast. The results indicate that the proposed dichromatic sensor could be used as a visual sensing platform for the direct detection of CD81 in biological samples and demonstrate its potential in preeclampsia diagnosis.
子痫前期（PE）严重影响孕妇和胎儿的健康，并导致孕产妇严重并发症。CD81已被确认为一种具有巨大潜力的新型PE生物标志物。在此，首次提出了一种基于等离子体酶联免疫吸附测定（等离子体ELISA）的超灵敏双色生物传感器，用于CD81在PE早期筛查中的应用。在这项工作中，基于金离子的HO双催化还原途径设计了一种新型显色底物[（HAuCl）-（N-甲基吡咯烷酮）-（NaCHO）]。金离子的两条还原途径由HO控制，这确保了金纳米颗粒的合成和生长对HO敏感。HO的量与CD81的浓度相关，并指导该传感器中不同尺寸金纳米颗粒的产生。当存在分析物时会产生蓝色溶液。当不存在分析物时，溶液变为红色。因此，由于红色和蓝色的吸收峰不同，可以进行双峰检测，然后产生两个检测信号，一个在550nm处的开启信号，另一个在600nm处的关闭信号。该方法对0.1 - 1000 pg/mL范围内的对数CD81浓度呈现线性响应，在两个波长下的检测限分别为86 fg/mL和152 fg/mL。由于血清引起的非特异性显色导致的假阳性率较低，产生了更强的颜色对比度。结果表明，所提出的双色传感器可作为一种视觉传感平台，用于直接检测生物样品中的CD81，并证明了其在子痫前期诊断中的潜力。
