Zheng Yun, Li Jianding, Zhou Bingpu, Ian Hou, Shao Huaiyu
Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, 999078, China.
Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, 999078, China; School of Science, Huzhou University, Huzhou, 313000, China.
Biosens Bioelectron. 2021 Apr 15;178:113021. doi: 10.1016/j.bios.2021.113021. Epub 2021 Jan 21.
Immunosensors are molecular recognition-based solid-state biosensing devices, in which the immunochemical reactions are coupled with transducers. As biologic or biochemical substances produced by tumor cells, tumor marker plays an important role in clinical diagnosis and treatment of cancer because its concentration is related to tumor size, clinical stage, and predicting prognosis. Voltammetric immunosensors based on the electrochemical analysis technique provide a sensitive electroanalytical approach for quantitatively detecting tumor markers by measuring the current as a function of the potential. To satisfy the need for accurate monitoring of tumor markers in low-concentration and their slight changes in concentration, the primary aim of developing a novel voltammetric immunosensor is to improve its sensitivity and limit of detection. Compared with traditional immunoassay, the advanced sensitivity-amplified immunosensors have applied appropriate amplification strategies to convert the bio-signal of antigen-antibody recognition events to the high electrochemical signal of redox species. Building on the significant concepts, sensitivity and limit of detection, we describe how the performance of voltammetric immunosensors can be improved by various sensitivity amplification mechanisms: (1) construction of labels with a high loading of signal species; (2) introduction of interfacial reaction initiated by functionalized nanomaterials; (3) building a synergistic connection between labels and substrate. The review ends with a summary of the shortage of current sensitivity amplified immunosensors and the perspective of enhancement strategies for more simple, efficient, and reliable voltammetric immunosensors.
免疫传感器是基于分子识别的固态生物传感装置，其中免疫化学反应与换能器相耦合。肿瘤标志物作为肿瘤细胞产生的生物或生化物质，因其浓度与肿瘤大小、临床分期及预后预测相关，在癌症的临床诊断和治疗中发挥着重要作用。基于电化学分析技术的伏安免疫传感器通过测量电流随电位的变化，为定量检测肿瘤标志物提供了一种灵敏的电分析方法。为满足对低浓度肿瘤标志物及其浓度微小变化进行精确监测的需求，开发新型伏安免疫传感器的主要目标是提高其灵敏度和检测限。与传统免疫分析相比，先进的灵敏度放大免疫传感器应用了适当的放大策略，将抗原 - 抗体识别事件的生物信号转化为氧化还原物质的高电化学信号。基于灵敏度和检测限这些重要概念，我们描述了如何通过各种灵敏度放大机制来提高伏安免疫传感器的性能：（1）构建具有高信号物质负载量的标记物；（2）引入由功能化纳米材料引发的界面反应；（3）在标记物和底物之间建立协同连接。综述最后总结了当前灵敏度放大免疫传感器的不足以及更简单、高效和可靠的伏安免疫传感器增强策略的展望。
