Abstract:

The precision and depth of our understanding push the chemical measurement is to achieve high sensitive detection of single entities, e.g., single cells, single nanoparticles, single nanobubbles, and single molecules. Electrochemistry stands out as ha direct and effective method for measuring electron transfer processes. High-resolution electrochemical measurements enable precise analysis of redox reactions at micro/nanoscale interfaces, yielding unique electrochemical signals from each entity, and revealing hidden inter-individual differences that are often covered by averaging effects. Various nanostructures, including ultramicroelectrode, nanopipette, nanotip, and nanopore, have been developed to construct electrochemical sensing interfaces that match the size of individual analytes with high spatial resolution and high-sensitivity. Advances in instrumentation enable the high temporal resolution and weak current detection, facilitating the real-time monitoring the dynamic electrochemical processes ranging from sub-milliseconds to microseconds. This capability supports the high-throughput and rapid sensing in solution, enabling identification of rare subpopulations, discovery of reaction intermediates, and mapping of dynamic interaction pathways. For example, nanopore technologies enable single biomolecule sequencing and sensing that can be applied to early and precise diagnosis. Electrochemical measurements at the single-particle level reveal intrinsic heterogeneity of structure-activity relationship for nanomaterials. In-situ electrochemical analysis of individual cells also provide insights into intracellular and inter-cellular biochemical processes while enhancing our understanding of mechanisms related to cell-to-cell communication networks. In recent years, significant advancements have been made in single-entity electrochemical measurements, including developments in nanointerfaces, ultra-sensitive instrumentation, and intelligent data analysis, providing new tools for the studies in micro-/nanomaterials, life sciences, and energy catalysis.

The Single-Entity Electroanalysis special issue (2024, Issues 10 and 11) brings together cutting-edge research from teams with extensive experience in single-entity electroanalysis field, featuring five papers, including two review papers and three research papers. This issue covers a range of innovative work, such as “Single Nanobubble Formation on Au Nanoelectrodes and Au@WS₂ Nanoelectrodes: Voltammetric Analysis and Electrocatalysis”, “Precision Delivery Using Nanopipette for Single-Cell Studies”, “Highly Sensitive Detection of Strontium Ions Using Metal-Organic Frameworks Functionalized Solid-State Nanochannels”, “Platinum Nanoparticle-Based Collision Electrochemistry for Rapid Detection of Breast Cancer MCF-7 Cells”, “Single-entity collisional electrochemistry (SECE) at the micro- and/or nano-interface between two immiscible electrolyte solutions (ITIES)”.

We hope this special collection will provide the knowledge to the readers for conducting in-depth studies in single entity electrochemistry in China. With this preface, we would like to express our heartfelt thanks to all the authors, reviewers and editorial staff for their hard and fruitful work!