Despite advancements in wearable plant sensor technologies, the development of high-performance sensors suitable for real agricultural applications remains limited. In this work, we developed a wearable plant electrochemical sensor by fabricating a hybrid electrocatalyst of iron oxide nanocubes incorporated onto carbon nanotube nanoribbons (IONCs-CNRs) with a gelatin hydrogel-based semisolid electrolyte, assembled in a sandwich-like structure. This biocompatible wearable sensor offers a high surface area, excellent conductivity, enhanced electrocatalytic activity, and good mechanical properties, enabling efficient and non-destructive detection of N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (6-PPD) contaminants in living plants. The hybrid catalyst exhibited an impressive 500 % enhancement in electrocatalytic activity compared to IONCs alone, highlighting its superior efficiency. These distinct properties enabled systematic optimization, resulting in impressive analytical performance, featuring a wide 6-PPD dynamic detection range of 100 nM to 18.8 µM along with an excellent sensitivity of 26.4861 µAµM