A disposable paper-based microfluidic electrochemical cell equipped with graphite-supported gold nanoparticles modified electrode for gallic acid determination

The combination of mu PAD with electrochemical transducers has gained advantages of miniaturization, high sensitivity, selectivity, simplicity of instrumentation, portability, rapid analysis, and so on. In this work, the development of a 3D paper-based microfluidic electrochemical device (3D-ePAD) for the determination of gallic acid (GA) was presented. The 3D-ePAD is composed of three electrodes (working, reference, and counter electrodes) in which the hydrophilic area of the working electrode was manually screen-printed and modified with graphite-supported AuNPs(AuNPs/C) ink. The evaluation of the electrochemical oxidation process of GA at modified and unmodified electrodes at 3D-ePAD indicated the improvement of anodic current responses at the AuNPs/C modified electrode which can be attributed to the intermolecular hydrogen-bonded network between AuNPs and GA. For quantitative determination of GA, the amperometric experiments were investigated under optimal conditions in which a linear relationship between the GA concentration and the recorded current was achieved. The sensor displays a good linear range of 1.0 to 100.0 mu M and 0.1 to 2.0 mM for GA determination. The limit of detection (LOD) of 0.89 mu M was achieved for GA by 3D-ePAD. Conclusively, the 3D-ePAD was performed successfully for the determination of GA in tea samples.

Automated summary

The development of a 3D paper-based microfluidic electrochemical device (3D-ePAD) for gallic acid determination was successfully demonstrated. The device exhibited a good linear range and low detection limit, making it suitable for the determination of gallic acid in tea samples.