Abstract: Recent studies indicate that the role of endogenous serotonin (5-HT) in gastrointestinal motility is still highly controversial. Although electrochemical technique allows for direct and real-time recording of biomolecules, the dynamic monitoring of 5-HT release from elastic and tubular intestine during motor reflexes remains a great challenge, because of the specific peristalsis patterns and inevitable passivation of sensing interface. Here, a stretchable sensor with anti-fouling and decontamination properties was developed by successive assembling gold nanotubes, titanium dioxide nanoparticles and carbon nanotubes. The formed sandwich structure endowed the sensor with satisfying mechanical stability and electrochemical performance, high resistance against physical adsorption, and superior efficiency to photodegrade biofouling. Rolling this sensor and inserting it into the lumen of rat ileum achieves successful mimicking intestinal peristalsis, and simultaneous real-time monitoring of distension-evoked 5-HT release for the first time. Our results unambiguously disclosed that mechanical distension of the intestine induces endogenous 5-HT overflow, and 5-HT level is closely associated with the physiological or pathological states of the intestine.

DOI: 10.1002/anie.201913953