Flexible self-supporting laser-induced graphene electrode devices for highly sensitive electrochemical analysis of Allura Red

Flexible self-supported laser-induced graphene (LIG) electrode devices were facilely fabricated through laser ablation technique by employing commercial polyimide film as the precursor material. Compared with the widely used traditional glassy carbon electrodes, the resulted LIG electrodes displayed abundant porous structure and surface defects. Notably, the one-step yielded LIG electrode devices were endowed with large electrochemically active surface area and accelerated electron transfer ability. Benefiting from its superior electrochemical property, these unmodified LIG electrodes exhibited remarkable enhanced electrochemical oxidation reactivity toward the food additive molecule Allura Red. Based on the augmented oxidation signal of Allura Red molecules on the LIG electrodes, a novel electrochemical sensor with high sensitivity for the detection of Allura Red was successfully developed. The sensor demonstrated a linear detection range spanning from 5 nM to 1 μM and exhibited a detection limit as low as 2.5 nM. Besides, the sensitivity was calculated to be 240.62 µA μM−1 cm−2. More importantly, the sensor manifested outstanding stability, reproducibility, and practicality, further emphasizing its potential for real-world application.