A host-based antifouling gold nanotube sensor for the selective detection of mechanically sensitive serotonin release...

Intestinal mucosal secretion is central to coordinating the gut microenvironment with mechanical signals. Yet, in situ monitoring of small-molecule in the intestine remains challenges because of the distinctive mechanical deformation and highly biofouling environment. Here, we introduce a sensing interface inspired by the host-guest molecular recognition. A stretchable electrode was constructed by co-electrodepositing 2-hydroxypropyl-β-cyclodextrin (HC) and poly(3,4-ethylenedioxythiophene) (PEDOT, P) onto the conductive gold nanotubes (Au NTs) framework. This approach couples the deformation-tolerant electrochemical performance of Au NTs with HC-enabled selective recognition of serotonin (5-HT), while effectively mitigating biofouling in complex biological environment. The resulting Au@HCP NTs sensor enables dynamic capture of mechanically evoked 5-HT release from enterochromaffin cells (ECs) under biomimetic stimulation, spanning both cellular and tissue-level readouts. Beyond monitoring, we further conceptualize ECs mechanosensory plasticity as an immunomodulatory node. Diverse microbial mimetics elevate ECs-derived 5-HT, and the platform reveals 5-HT signaling as a core mechanism that integrates immune information with mechanosensation in ECs. Collectively, this work establishes a host-guest recognition-based strategy for real-time small-molecule monitoring in complex, mechanically dynamic environments, offering a generalizable route toward in situ sensing under unique mechanical demand.