Confined Controlled Electrochemistry

In this perspective, we map the conceptual and technological evolution of the electrochemical interface over the past several decades, highlighting how our understanding has expanded from classical static boundaries to dynamic multidimensional interphases. Based on the increasing spatial complexity and the emergence of temporal resolution, we categorize interface development into four dimensions: from one-dimensional (1D) metal–electrolyte junctions for bulk concentration sensing, through 2D chemically modified interfaces (e.g., self-assembled monolayers) and 3D biointerphases (e.g., lipid membranes), to 4D nanopore systems capable of capturing real-time single-molecule events. Special emphasis is placed on nanopore electrochemistry as a single-biomolecule interphase, enabling real-time detection of single-molecule conformational dynamics, post-translational modifications, and noncovalent interactions at atomic resolution. We highlight the potential of nanopore sensing in DNA/protein sequencing, single-molecule catalysis, and beyond.