A photoelectrochemical sensor array based on MOF nanozymes for the identification and detection of phenolic compounds

The wide variety of phenolic compounds, along with their similar structural features and physicochemical properties, poses significant challenges for reliable identification and detection. This article develops a novel photoelectrochemical (PEC) sensor array based on three metal-organic framework (MOF) nanozymes with substrate diversity and an efficient PEC sensing platform, achieving accurate identification and detection of six phenolic compounds. MOF nanozymes (ZIF-8, D-ZIF-67 and MIL-88B) catalyze the oxidation of phenolic compounds, yielding distinct quinone derivatives. These quinone derivatives are coupled to the surface of the PEC sensing platform with chitosan (CS) as the recognition element and BiOI as the signal transduction element, generating unique PEC response fingerprints for recognition and detection. This sensor array is the first report of a phenolic compound sensor array based on MOF nanozymes integrated with a PEC sensing platform, avoiding the limitations of sample color and turbidity on detection. In addition, inheriting the high sensitivity advantage of PEC technology, the developed sensor array can accurately identify phenolic compounds with concentrations as low as 1 μM, and achieve quantitative detection of two model targets, catechol and dopamine, with a linear range of 1-100 μM. This study provides a new approach for the identification and detection of phenolic compounds, and contributes to the advancement of PEC sensor arrays.