A focus on capacitive cation sensing under flow: play it again SAM.

We highlight an article by Patrick (S. C. Patrick, R. Hein, P. D. Beer and J. J. Davis, , 2024, https://doi.org/10.1039/D4SC05271D) that integrates capacitance spectroscopy with a continuous flow assay to achieve reagentless electrochemical sensing. Injection of analytes leads to ion recruitment by the self-assembled monolayer (SAM) of benzo-15-crown-5 receptors generating spikes in the sensorgram. Injecting the supporting electrolyte regenerates the vacant receptor, returning the value to baseline. Binding and debinding kinetic signatures also emerge. The continuous and sensitive reporting of interfacial host-guest binding in real-time follows the precision of a well-composed melody that can be played again and again.