Metal anchoring strategy: electrochemical sensor with excellent performance in gastrointestinal secretions

In order to monitor the health level of the digestive tract, especially to achieve real-time monitoring of 3,4-dihydroxyphenylalanine (DA) and uric acid (UA) levels in saliva. This work proposes a strategy for in situ adsorption of Au³⁺ ions in HKUST-1 pore and in situ reduction to Au⁰, anchoring in HKUST-1 pores. Au@HKUST-1 maintaining stability in complex environments lays the foundation for its application in gastrointestinal monitoring. The sensor was successfully prepared by Au@HKUST-1 which can achieve real-time monitoring of DA and UA. The excellent monitoring performance is attributed to the strong interaction between Au⁰ and HKUST-1, which enables Au@HKUST-1/GCE to exhibit excellent monitoring performance for DA, UA and mixtures, with detection limits of 0.06, 0.38, 0.10, and 0.15 µM, respectively. In artificial saliva, Au@HKUST-1/GCE has demonstrated excellent recovery rates, providing feasible strategies for monitoring and timely intervention in gastrointestinal diseases.