Separate and simultaneous determination of vanillin, theophylline and caffeine using molybdenum disulfide embedded polyaniline/graphitic carbon nitrite nanocomposite modified glassy carbon electrode

Abstract

Electrochemical detection and quantitative analysis VAN, TP and CAF in food stuffs, energy drinks and pharma products using modified MoS2/PANI@g-C3N4 electrode (GCE) has been fascinating researches for many years. In this study polyaniline (PANI), molybdenum disulfide (MoS2) and graphitic carbon nitride (g-C3N4) nanocomposite modified glassy carbon electrode (MoS2/PANI@g-C3N4/GCE) was successfully used for separate and simultaneous sensing of vanillin (VAN), theophylline (TP) and caffeine (CAF). Compared to pure g-C3N4/GCE, MoS2/GCE and PANI/GCE, with MoS2/PANI/g-C3N4@GCE displayed high sensitivity and good selectivity and electrocatalytic activity towards the oxidation of VAN, TP and CAF under optimal experimental conditions. The modified electrode was also used simultaneous detection of VAN, TP and CAF, with high oxidation peak currents and well separated voltammetric peaks, using differential pulse voltammetry measurements. The sensitivity of the fabricated electrode was 8.5 μAμM−1 cm−1, 10.43 μAμM−1 cm−1 and 6.96 μAμM−1 cm−1 and the limit of detection (LOD) was estimated to be 0.043, 0.052 and 0.061 μM for VAN, TP and CAF, respectively. Furthermore, the modified electrode exhibited excellent stability and good reproducibility. In addition, the MoS2/PANI@g-C3N4 electrode was also successfully employed for the determination of these three species in real samples like food stuff, energy drinks and pharma products. These results demonstrate that the MoS2/PANI@g-C3N4 composite modified GCE could be a promising electrode material for the development of high-performance electrochemical sensor.