Development of molybdenum trioxide based modified graphite sheet electrodes for enhancing the electrochemical sensing of dopamine

Electrochemical detection of dopamine is crucial in the early stages of Parkinson's and Alzheimer's disease diagnosis. In this paper, we have developed modified electrodes based on molybdenum oxide (MoO3) grown on graphite sheet (GS), which was investigated for its ability to detect dopamine sensitively and selectively. The MoO3/GS electrodes were prepared by thermal evaporation of MoO3 on GS sheets followed by annealing at different temperatures (RT and annealing temperatures of 100 degrees C, 200 degrees C, 300 degrees C, 400 degrees C and 500 degrees C). The electrodes were analysed using XRD, Raman, FESEM and HRTEM. Compared to other electrodes, the modified MoO3/GS electrode annealed at 500 degrees C showed more significant charge transfer and increased selectivity and sensitivity in the electrochemical detection of dopamine. The findings showed a significant sensitivity of 85.71 mu A. mu M-1<middle dot>cm(-2) for the linear range of 1-10 nM and the lowest detection limit of 2.71 nM were achieved from the dopamine sensing. The developed electrode successfully detected dopamine in human blood serum and urine samples with respectable recovery rates.