Ultra-selective and real-time detection of dopamine using molybdenum disulphide decorated graphene-based electrochemical biosensor

Picomolar level electrochemical detection of hydroquinone, catechol and resorcinol simultaneously using a MoS2 nano-flower decorated graphene

“…12,38 Further, the peak at 236.2 eV corresponds to Mo 6+ due to the C–O–Mo indicating bond formation between the O-functional groups of pGr and MoS 2 . 32 This result supports the predicted structure of pGr-MoS 2 , where MoS 2 are bonded through the hydrophilic oxygen functionalities which are at the edges of the pGr sheets. The detailed XPS analysis results for C 1s, O 1s, Mo 3d and S 2p are discussed in detail in the ESI †.…”

“…The pGr-MoS 2 was synthesized using the method reported by our group elsewhere. 32 The significance of this synthesis is mainly in the use of pGr, 12 which is Gr obtained by pulverizing graphite and has a better aromatic structure compared to the rGO and has oxidized groups located mainly on the edges. Therefore, in pGr-MoS 2 , the MoS 2 nanostructures are expected to attach to the edges of the pGr sheets through the oxygen-containing functional groups.…”

“…S1C†) corresponding to E 1 2g & A 1 g vibrational modes of the nano-MoS 2 and D, G, & 2D bands of the pGr, respectively. 11,30–32 The sharp peaks in the XRD pattern (Fig. 1D) indicates crystalline nature, and the peaks at 2 θ = 26.5° with a d spacing of 0.41 nm corresponds to the reflections of graphitic (002) plane, and the peak indexed at 15.2°, 32.6°, 43°, and 57° reflects MoS 2 planes (002), (004), (103), and (006).…”

“…The procedure for the synthesis of the pGr-MoS 2 by our group is reported in detail elsewhere. 32 The pGr, sodium molybdate dihydrate, and thioacetamide were used as the precursors and synthesis was carried using a hydrothermal method.…”

“…In a succeeding work, we had demonstrated the ultra-selectivity towards DA when the pGr was combined with MoS 2 to form pGr-MoS 2 , which surpassed the selectivity property of all the other reported non-enzymatic/enzymatic DA sensors by exhibiting current response solely for DA in the presence of neurotransmitters of similar structure and other biomolecules. 32 The selectivity was attributed to the aromatic structure of pGr, which preferentially adsorbed DA and the ultra-selectivity to the masking of the functional groups of pGr by MoS 2 , which prevented the possible interaction of other biomolecules of similar structure through the functional groups. Inspired by this result, we explored the possibility of using the pGr-MoS 2 for the EC sensing of DHBI, which has an aromatic ring and structure similar to that of DA.…”