Sintered gold nanoparticles as an electrode material for paper-based electrochemical sensors

A simple and economical process for fabricating gold electrodes on paper is presented. Gold nanoparticles stabilised with 4-(dimethylamino)pyridine were applied to nail-polish coated filter paper and made conductive using a camera flash sintering step. To test the ability of the sintered gold nanoparticle film to function as a sensing platform, cysteine was self-assembled on gold and used for the electrochemical determination of copper ions. The cysteine-sintered gold nanoparticle film was able to successfully complex copper ions, with only minor differences in performance compared with a standard cysteine-modified solid-state gold disk electrode. Investigations by Raman spectroscopy revealed the successful removal of the 4-(dimethylamino)pyridine coating during sintering, whereas electrochemical impedance spectroscopy and scanning electron microscopy suggested that differences in the sensing performance could be attributed to the rougher morphology of the sintered gold nanoparticle electrode.