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

Abstract

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 μg 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.

Print-Light-Synthesis for Single-Step Metal Nanoparticle Synthesis and Patterned Electrode Production

“…Apart from creating nanoparticle-decorated electrodes, complete stand-alone thin-film metal electrodes are also of interest for electrochemical applications, as they do not require a conductive support and can be printed directly on an insulating substrate. In a very recent work, Maiorano, Gianvittorio et al applied Print-Light-Synthesis to generate thin gold films as electrodes on a flexible substrate using a mercury arc lamp [ 26 ] ( Figure 6 ). The advantage of using this lamp over the flashlamp is its smaller size and lower costs.…”

“…Introduction of a layer of air, which is a poor heat conductor, increases the local temperature of the substrate limiting pattern widening ( B ). Figure reproduced with permission (open access article distributed under the terms of the Creative Commons CC BY license) from [ 26 ].…”

Photo-driven Surfactant-Free Gold Nanostars for Rapid Bacterial Detection in Food Safety Using Surface-Enhanced Raman Spectroscopy

“…Given these challenges, the imperative for facile, rapid, scalable, and environmentally friendly (surfactant-free) strategies for synthesizing anisotropic gold nanomaterials tailored for SERS applications becomes evident. A promising approach is the photochemical synthesis of gold nanomaterials, − which offers advantages such as the absence of strong reducing agents, potential room-temperature operation, noninvasiveness, and precise space-selective control. Our prior work introduced a green and straightforward method for gold nanosphere synthesis via photoreduction using methanol as an electron acceptor, obviating the need for external surfactant additives or stabilizers and completing the process within 20 min.…”