Simultaneous detection of dopamine and ascorbic acid using silicate network interlinked gold nanoparticles and multi-walled carbon nanotubes

In this manuscript, we report a facile and environmental friendly procedure for the aqueous synthesis of gold nanoparticles (∼3–8 nm) and functionalized multiwalled carbon nanotubes (MWCNT) interlinked through bi-functionalized silicate molecule N-[3(trimethoxysilyl)propyl]ethylenediamine (EDAS). The complexes, denoted by MWCNT–EDAS–AuNPs, were then characterized by UV–visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), and atomic force microscope (AFM). In addition, it is also fabricated on glassy carbon electrodes to simultaneously detect ascorbic acid (AA) and dopamine (DA) using an electrochemical technique. MWCNT–EDAS–AuNPs can act as a modified electrode and show a wide linear response for AA and DA in the concentration range of 1 × 10−7–9 × 10−6 M and 1 × 10−7–8 × 10−6 M with detection limits of 0.07 and 0.08 μM at S/N = 3, respectively. These results have demonstrated that MWCNT–EDAS–AuNPs are a promising candidate as advanced electrode material in electrochemical sensing of AA and DA simultaneously in pharmaceutical samples.

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