Electrochemical Immunoassay of Endothelin-1 Based on a Fenton-Type Reaction Using Cu(II)-Containing Nanocomposites as Nanozymes

Abstract

Endothelin-1 (ET-1) is a powerful endogenous vasoconstrictor and it is closely related to the pathogenesis of endothelial dysfunction that is commonly involved in the initiation of vascular inflammation and in the development of vascular diseases. A new method for the electrochemical immunoassay of ET-1 was put forward in this work. ET-1 antibodies (Ab), gold nanoparticles (GNPs), and copper ions were employed to synthesize nanoenzyme-labeled antibodies, Ab-GNPs-Cu(II) nanocomposites, and the latter was evaluated using transmission electron microscopy, dynamic light scattering, UV−vis absorption spectrophotometry, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. These nanocomposites could be captured on a glassy carbon electrode (GCE) modified with poly(thionine) (PTH) and ET-1, GCE/PTH/ET-1. The immobilized nanoenzymes, GNPs-Cu(II) nanoparticles, played a peroxidase mimic role. Hydroxyl radicals, • OH, generated by a Fenton-type reaction, oxidized PTH and induced the considerable cathodic current on an assembled sandwich-type electrode. Owing to the competitive immunoreaction, ET-1 in the solution inhibited the capture of Ab-GNPs-Cu(II) nanocomposites. The deficiency of • OH caused the decline of the electrochemical response. The cathodic current change was in proportion to the ET-1 concentration from 0.5 to 500 ng mL −1 . Cell morphology and viability investigations show that human umbilical vein endothelial cells, HUVECs, suffered from dysfunction when they were incubated in the presence of high-concentration glucose. Analyses on the growth medium using the developed method reveal that ET-1 was secreted by the injured cells and the release level of ET-1 was associated positively with the glucose concentration in the growth medium.

Renal Hypoxic Reperfusion Injury-on-Chip Model for Studying Combinational Vitamin Therapy

“…ET-1 is the most abundant biomarker released explicitly by endothelial cells to induce vasoconstriction and expand the destructive effect of RHR injury. 35 In addition, ET-1 performs upregulation in RHR injury. Hence, several therapeutic agents are being introduced to limit the localized release of ET-1.…”

“…The role of endothelial cells in RHR injury is crucial as they produce several cytokines that modulate the microvasculature for protecting renal tissue from the oxidative burst. ET-1 is the most abundant biomarker released explicitly by endothelial cells to induce vasoconstriction and expand the destructive effect of RHR injury . In addition, ET-1 performs upregulation in RHR injury.…”

Practical Exploration on Mutual Promotion between Teaching in Analytical Chemistry (I) and Scientific Research

“…教学团队秉承"学生中心"理念，针对分析化学理论课和实验课开展了教学模式和教学方法改 革 [13,14] 。为了实现分析化学(一)教学与科研的相互促进，教学团队进行了积极探索。 2.1 科研成果融入教学内容 笔者在分析化学(一)课程教学过程中精心挑选了一批分析化学科研论文作为教学素材和课外阅 读资料，其中以刊载教师本人科研成果的论文为主，赋予了该课程明显的特征。 在讲解"酸碱缓冲溶液"以及"配位滴定滴定剂EDTA性质"知识点时，教师展示了三篇文献 [15][16][17] 。 这些文献报导了笔者近年来在血管内皮细胞损伤标志物血栓调节蛋白(TM)、血管性血友病因子 (vWF)和内皮素-1 (ET-1)检测方面的研究工作，涉及压电传感、电化学测量等不同的分析方法。教师 以pH 7.4生理磷酸盐缓冲溶液(PBS)开场引入酸碱缓冲溶液的概念，推导缓冲溶液pH计算公式后，要 求学生讨论并设计一定体积0.1 mol•L −1 pH 7.4 PBS配制的实验方案，教师进行点评和总结，让学生 知晓无论是在化学分析还是仪器分析中缓冲溶液都是最常用的试剂之一。在讲授EDTA性质时，以 "细胞消化液中为何含有EDTA"为题给学生布置课外阅读作业，要求查阅相关科研文献撰写微报告， 丰富了平时考核的方式。上述实例的运用，目的在于使学生了解基础知识的实际应用价值，培养探 索精神，也给学生传递了重要的理念：现代科学研究的基础是不同学科知识的交叉融合。 在讲解"物质对光的选择性吸收"知识点时，教师选择报导荧光检测TM的文献 [18] 。在该研究中， 笔者的研究小组分别合成了纳米金和抗体修饰纳米金并测量了两者分散液的紫外-可见吸收光谱。课 堂教学中，教师首先展示了酒红色纳米金溶液和紫红色的抗体-纳米金复合物溶液的图片，要求学生 基于互补色原理预测两者吸收峰的大致位置(500-560 nm)，之后教师展示实验测量的吸收曲线。随 后，教师组织学生分组讨论为何抗体-纳米金复合物相对于纳米金其吸收峰位置会发生红移。通过预 测-验证-讨论-总结等一系列师生高效互动环节， 营造活跃的课堂氛围， 实现课堂教学由 "教师中心" 到"学生中心"的转变。 在讲解"回归分析法"知识点时，教师介绍回归方程相关公式后，提供上述四篇文献 [15][16][17][18] 中谐 振频率变化值(Δf 0 )、荧光强度差值(ΔF)、电流强度差值(ΔI)和检测物TM、vWF和ET-1的浓度c等实验…”

A highly efficient electrochemical sensor containing polyaniline/cerium oxide nanocomposites for hydrogen peroxide detection

“…Those nanocomposites have demonstrated exceptional performance in a variety of domains, making them appropriate for a broad range of real-world applications. [1][2][3][4] The above multifunctional materials have a wide range of applications, along with the construction of different kinds of sensors. [5][6][7] The nanollers, which seem to be nanoscale in size and have a highly porous structure, are the primary reasons for the vast uses of nanocomposites.…”