Laser synthesis and tailor-design of nanosized gold onto carbon nanotubes for non-enzymatic electrochemical glucose sensor

• Nanostructured Au films were grown on carbon nanotubes by pulsed laser deposition.
• The growth of gold was conducted under vacuum and under helium pressure.
• The electroactivity was studied by voltammetry and square wave voltammetry.
• Au films made under vacuum show superior activity towards glucose oxidation.
• We report a promising CNT/Au electrode for non-enzymatic glucose sensor.

The non-enzymatic cyclic and pulse voltammetric detection of glucose using pulsed laser deposited gold nanostructures onto carbon nanotubes electrodes is described for the first time. Several synthesis conditions have been considered in order to obtain various morphologies for the Au film. Among all the synthesized Au nanostructures, it is found that an Au film deposited under vacuum with 10,000 laser pulses displays a high electroactive surface area of 6.55 cm2 and a roughness factor of 13.2. In addition, this electrode exhibits a low onset potential of −0.28 V vs. Ag/AgCl for glucose oxidation. A linear square-wave voltammetric response for oxidation of glucose was observed up to a glucose concentration of 50 mM with a sensitivity of 25 μA cm−2 mM−1 and a detection limit of 0.1 mM. Finally, owing to its versatile capabilities such as robust control of the surface morphology, control of the stoichiometry and ultra-low loading of noble catalyst, it can be expected that the pulsed laser deposition (PLD) technique will emerge as a fabrication tool for on chip miniature-sized sensors in the near future.