Synthesis and characterisation of molybdenum disulphide dispersed poly(1-naphthylamine) nanocomposites for enzyme-free electrochemical sensing of dopamine

Abstract

Recently, research on conducting polymer nanocomposites containing graphene analogues has generated considerable interest. The electrochemical applications of novel poly (1-naphthylamine)-molybdenum disulfide (PNA-MoS2) nanocomposites synthesised by in-situ oxidative polymerization of NA with varying quantities (0–30% by weight) of ultrasonically dispersed MoS2 layers are investigated in this paper. The structural, electrochemical, optical, and thermal properties of synthesised PNA-MoS2 nanocomposites were found to be varied according to MoS2 content. Investigations using electron microscopy and X-ray diffraction confirmed the formation of nanocomposites, in which PNA chains were partially intercalated between ultrasonically exfoliated MoS2 layers. In terms of conductivity, capacitance, and charge transfer, PNA-MoS2 nanocomposites outperformed bare MoS2 and pure PNA, with 20% MoS2 providing the greatest results. Enhanced electrochemical performance was attributed to the high surface area and distinct redox characteristics resulting from the synergistic interaction between the conjugated backbone of PNA and polar MoS2. Moreover, CV experiments utilising carbon paste electrodes modified with PNA-MoS2 nanocomposites demonstrated enhanced electrocatalytic efficiency for dopamine (DA) oxidation, with electrochemical processes governed primarily by diffusion. The development of a low-cost voltammetric DA sensor with a broad detection range (15–100 [μM]), high sensitivity (860 [μA mM−1 cm−2], and a low detection limit of 0.26 [μM] is presented.