Carbon Nanotube, Carbon Black and Copper Nanoparticle Modified Screen Printed Electrodes for Amino Acid Determination

Screen-printed electrodes have been used for the determination of amino acids, focussing particularly on tryptophan, following different surface modifications by carbon nanotubes (CNT), carbon black (CB) and copper nanoparticles. The modified electrodes were characterised by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. Detection by square wave voltammetry was improved by further surface modification with copper nanoparticles, exhibiting efficient electrocatalytic activity towards amino acid oxidation with high sensitivity, stability and long shelf-life. The applicability of a low-cost, robust carbon black substrate using the synergetic electrocatalytic effect provided by copper nanoparticles for amino acid sensing is demonstrated.