CuNPs decorated molecular imprinted polymer on MWCNT for the electrochemical detection of l-DOPA

Abstract

A novel synthesis of copper nanoparticle (CuNPs) is carried out by the reduction of ethylene diamine Cu complexes using sodiumborohydride as reducing agent. The synthesized copper nanoparticle is grafted with molecular imprinted polymer on MWCNT (CuNPs/MWCNT-MIPs). Fabricated sorbent is used for the molecular recognition and sensing of levodopa (l-DOPA) in human urine and pharmaceutical samples. The non covalent interaction between l-DOPA and the functional groups present in the selective binding sites of the polymer composite sorbent is mainly responsible for the recognition property. The synthesis of CuNPs decorated MWCNT-MIPs and its extents are characterized by employing UV–Vis spectroscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy techniques. The electrochemical investigation shows that the imprinted (CuNPs/MWCNT-MIP) material has good recognition capacity towards l-DOPA. The sensitivity is found to be directly proportional to the concentration of template with a detection limit of 7.23 × 10−9M (S/N = 3). The specificity and selectivity of the fabricated sensor give a fine discrimination between l-DOPA and structurally related compounds such as dopamine, uric acid, 3,4-Dihydroxyphenylacetic acid and homovanillic acid. Keywords: Electrochemical sensor, Molecular imprinted polymer, MWCNT, Copper nanoparticle, l-DOPA