Recent advances in pillar[n]arene-based (photo)electrochemical sensors

Electrochemical and photoelectrochemical detection techniques have been widely applied in fields such as bioanalysis, environmental monitoring, and food safety due to their rapid response, operational simplicity, and high sensitivity. However, achieving highly selective recognition of target analytes in complex samples, enhancing sensitivity for trace analysis, and constructing stable electrode interfaces remain core challenges in this field. As the fifth-generation macrocyclic supramolecular hosts, pillar[n]arenes possess a unique pillar-shaped symmetrical structure, an electron-rich cavity, and readily functionalizable rims, enabling highly selective recognition of guest molecules through multiple non-covalent interactions. This provides new insights into addressing the above-mentioned challenges. This Feature Article systematically reviews the research progress of pillar[n]arenes in the field of electrochemical and photoelectrochemical detection. The related research work is summarized from two dimensions: first, the construction strategies for different types of pillar[n]arene-based electrode modification materials, including pure pillar[n]arene self-assembled materials, pillar[n]arene-metal nanocomposites, pillar[n]arene-inorganic nonmetallic nanomaterials, pillar[n]arene-metal/nonmetal hybrid nanomaterials, and cooperatively assembled materials based on two distinct types of pillar[n]arenes. Second, the applications of these pillar[n]arene-functionalized electrodes in the detection of various classes of substances, including biomarkers and disease-related substances, neurotransmitters and psychoactive substances, environmental pollutants and toxins, small biomolecules and metabolites, as well as inorganic active species. Finally, future development directions for pillar[n]arene-based electrochemical sensors are discussed, aiming to provide a reference for research on the rational design and applications of high-performance supramolecular electrochemical sensors.