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A disposable copper (II) ion biosensor based on self-assembly of L-cysteine on gold nanoparticle-modified screen-printed carbon electrode was fabricated. The electrode was modified by attaching gold nanoparticles onto the surface of screen-printed carbon electrode through seed mediated growth method followed by self-assembly of L-cysteine. As demonstrated by differential pulse voltammetry, the sensor exhibited high sensitivity to copper (II) ion down to ppb (parts per billion) levels. Optimization of various experimental parameters such as pH, buffer concentration, and preconcentration time, which influenced the performance of the biosensor, was investigated. The sensor demonstrated a wide linear response range from 10 to 0.005 ppm(r=0.9870), with a lower detection limit of 8 ppb using 10 min of preconcentration time. The sensor based on screen-printed electrode provides a cost-effective means of application of copper ion sensor for the detection of ppb level of copper ions in water.

Abstract. Disposal Copper (II) and aluminium (III) sensors based on gold nanoparticles-modified screen-printed carbon electrode were fabricated. The copper ion sensor was fabricated by attaching gold nanoparticles onto the surface of screen-printed carbon electrode through seed mediated growth method followed by assembly of L-cysteine. The aluminium ion sensor was fabricated by attaching gold nanoparticles onto the surface of screen-printed electrode through drop-coating method followed by self-assembly of mercaptosuccinic acid. As demonstrated by differential pulse voltammeter, both sensors exhibited high sensitivity towards copper (II) or aluminium (III) ions down to ppb (parts per billion) levels. Electrochemical behavior of gold nanoparticles attached onto the surface of screen-printed carbon was investigated in details in order to obtain optimum performance for both sensors.