Cyclodextrin-based architectures for electrochemical sensing: from molecular recognition to functional hybrids

This review surveys recent advances in the integration of cyclodextrins (CDs) with diverse materials for electrochemical detection of a wide range of analytes in environmental, pharmaceutical, and clinical contexts. CDs, featuring a hydrophobic cavity and a hydrophilic exterior, enable selective host-guest binding of small organic and inorganic molecules. By anchoring CDs onto electrode surfaces via strategies such as self-assembled monolayers, layer-by-layer deposition, or polymer entrapment, researchers have achieved improved selectivity and lower detection limits for target compounds. These CD-functionalized interfaces are further enhanced by combination with carbon nanotubes, graphene, metal nanoparticles, and redox mediators, providing synergistic effects that boost conductivity, catalysis, and signal amplification. Moreover, CD-based sensors exhibit reversible recognition, making them amenable to repeated use and continuous monitoring. Notably, derivatization of the CD ring expands its applicability, introducing functionalities such as chirality recognition, metal coordination, or improved solubility. Different detection modes, including voltammetry, impedance, and competitive displacement assays, have been reported for a variety of analytes, ranging from heavy metals and pesticides to pharmaceuticals and chiral compounds. The incorporation of CDs into advanced hybrid architectures also offers solutions to common issues like electrode fouling and limited selectivity, thus expanding their utility in harsh or complex sample environments. While challenges remain in ensuring reproducibility, large-scale manufacture, and robust performance in real-world applications, ongoing innovations in materials science and synthetic chemistry promise to make CD-based electrodes increasingly valuable for sensitive, portable, and cost-effective chemical analysis. Furthermore, novel integration with biological receptors, such as enzymes and aptamers, holds promise for multiplexed biosensing.