Mechanism elucidation for electrochemical simultaneous detection of multiple electron-rich phytohormones on a...

The challenge in achieving simultaneous electrochemical detection of multiple phytohormones stems from the intricacies involved in delineating oxidation mechanisms of multiple phytohormones, along with the precise delineation of peaks in the electrochemical profiles. Electron-rich phytohormones, which readily participate in electron transfer reactions, possess strong electron-donor properties and can drive redox processes in signal transduction. This work reports electrochemical simultaneous detection of multiple electron-rich phytohormones (indole-3-acetic acid, salicylic acid, and naphthaleneacetic acid) on a portable flexible sensor and virtual visualization. The approach integrates electrochemical investigations with theoretical computations to decipher the intricate oxidation mechanisms of these electron-rich phytohormones at the sensor interface. The number of electrons and protons transferred during the redox processes of the three electron-rich phytohormones were individually quantified via electrochemical method. Furthermore, through calculations and analysis of electronic structure properties-frontier orbital distribution, Fukui function, electroactive sites and oxidation reaction energy barriers-the structure-activity relationship governing the molecular oxidation process is clearly elucidated. This work not only establishes an experimental and virtual visualization platform for the rapid multicomponent electron-rich phytohormones electro-analysis, but also provides an in-depth clarification of their interfacial reaction mechanisms and electron transfer pathways. It reveals distinct differences in the electrochemical behaviors of these phytohormones, thereby advancing the field from empirical monitoring toward rationally designed detection systems.