Rare earth gallium garnets possess numerous applications due to their excellent physical and chemical properties. The bifunctional applications from Lu3Ga5O12 can indeed open a new era for gallium garnets. The electrochemical storage devices and electrochemical detection of pesticides using Lu3Ga5O12 offer a unique perspective to the other nanocomposites. Herein, Lu3Ga5O12 was synthesized via a simple citrate gel-matrix method. Analytical techniques such as XRD, Raman, UV-Vis Spectroscopy, FE-SEM, XPS and BET examined the phase purity, crystallinity, optical properties, surface morphology, oxidation state, pore size etc. Electrochemical measurements, including CV, GCD, and EIS, validate that the as-prepared Lu3Ga5O12 exhibits a remarkable specific capacitance of about 658 Fg−1 at 1 Ag−1. It also provides a higher capacitive retention rate of 88.41% for 5000 cycles at 5 Ag−1. It is then employed to fabricate an asymmetric device for its practical applications and exhibits a capacitive retention rate of about 74.88% and 95.02% of coulombic efficiency for 5000 cycles at 4 Ag−1. A simple, biocompatible sensing platform for the detection of imidacloprid was proposed. It establishes a linear relationship between sensing current and concentration from DPV with imidacloprid concentration ranging from 0.1 to 26 nM. The LOD obtained is 0.3 nM, thus enabling as a suitable sensor for practical accessibility.