Label-free electrochemical biosensing leverages the advantages of label-free techniques, low cost, and fewer user steps, with the sensitivity and portability of electrochemical analysis. In this review, we identify four label-free electrochemical biosensing mechanisms: ( a) blocking the electrode surface, ( b) allowing greater access to the electrode surface, ( c) changing the intercalation or electrostatic affinity of a redox probe to a biorecognition unit, and ( d) modulating ion or electron transport properties due to conformational and surface charge changes. Each mechanism is described, recent advancements are summarized, and relative advantages and disadvantages of the techniques are discussed. Furthermore, two avenues for gaining further diagnostic information from label-free electrochemical biosensors, through multiplex analysis and incorporating machine learning, are examined.

中文翻译：

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用于疾病检测的无标记电化学方法

无标记电化学生物传感利用了无标记技术、低成本和较少用户步骤的优点，同时具有电化学分析的灵敏度和便携性。在这篇综述中，我们确定了四种无标记电化学生物传感机制：（a）阻挡电极表面，（b）允许更多地接触电极表面，（c）改变氧化还原探针对生物识别单元的嵌入或静电亲和力，和（d）由于构象和表面电荷的变化而调节离子或电子传输特性。描述了每种机制，总结了最新进展，并讨论了这些技术的相对优点和缺点。此外，还研究了通过多重分析和结合机器学习从无标记电化学生物传感器获取进一步诊断信息的两种途径。