Print-Light-Synthesis of Gold Thin Film Electrodes for Electrochemical Sensing

The one-step fabrication of gold films by inkjet printing of a gold precursor ink and its photochemical reduction by exposure to UV light is presented. Inkjet printing creates on a substrate with high control micrometer-thin reaction volumes in which upon direct high-intensity light irradiation, the gold precursor reduces to pure and well-adhered Au particles, while all other ink components escape in the gas phase, without the need for any further post-treatment. The Au precursor ink does neither contain stabilizing agents, such as polymers or surfactants, nor sacrificial compounds, such as photoinitiators, to initiate and accelerate the reduction. This economic and green process is known as Print-Light-Synthesis (PLS) and is herein used to create gold patterns of thin compact Au films and separated Au nanoparticles. Gold loadings are in the mu g cm(-2) range and precisely controlled, thanks to the inkjet printing parameters. The gold films are characterized by spectroscopic and electrochemical methods. Finally, the applicability of Au films as electrochemical sensors is demonstrated for the detection of 1,4-butanediol in comparison to a commercial screen-printed Au electrode. The PLS Au electrode shows a 20 times higher sensitivity and opens new possibilities for disposable electrode production.

Automated summary

This article presents the one-step fabrication of gold films by inkjet printing of a gold precursor ink and its photochemical reduction by UV light exposure. The inkjet printing technique creates precise micrometer-thin reaction volumes on a substrate, allowing for direct light irradiation that reduces the gold precursor to pure and well-adhered Au particles. The process, known as Print-Light-Synthesis (PLS), is economic and environmentally friendly, eliminating the need for stabilizing agents or sacrificial compounds. The gold films have controlled gold loadings in the μg cm(-2) range and show high sensitivity as electrochemical sensors for the detection of 1,4-butanediol.