Nanostructure ITO and Get More of It. Better Performance at Lower Cost

Abstract

In this paper, we investigated how different growth conditions (i.e., temperature, growth time, and composition) allows for trading off cost (i.e., In content) and performance of nanostructured indium tin oxide (ITO) for biosensing applications. Next, we compared the behavior of these functionalized nanostructured surfaces obtained in different growth conditions between each other and with a standard thin film as a reference, observing improvements in effective detection area up to two orders of magnitude. This enhanced the biosensor’s sensitivity, with higher detection level, better accuracy and higher reproducibility. Results show that below 150 °C, the growth of ITO over the substrate forms a homogenous layer without any kind of nanostructuration. In contrast, at temperatures higher than 150 °C, a two-phase temperature-dependent growth was observed. We concluded that (i) nanowire length grows exponentially with temperature (activation energy 356 meV) and leads to optimal conditions in terms of both electroactive surface area and sensitivity at around 300 °C, (ii) longer times of growth than 30 min lead to larger active areas and (iii) the In content in a nanostructured film can be reduced by 10%, obtaining performances equivalent to those found in commercial flat-film ITO electrodes. In summary, this work shows how to produce appropriate materials with optimized cost and performances for different applications in biosensing.

Microenvironmental Behaviour of Nanotheranostic Systems for Controlled Oxidative Stress and Cancer Treatment

“…In the last few years, ITO remained one of the most researched materials for a variety of applications. It is an n-type semiconductor with a band gap of 3.2 eV [ 151 , 152 ]. It finds its main applications as liquid crystal display devices, electrochromic cells, solar cells and sensor modules [ 151 , 153 ].…”

“…It is an n-type semiconductor with a band gap of 3.2 eV [ 151 , 152 ]. It finds its main applications as liquid crystal display devices, electrochromic cells, solar cells and sensor modules [ 151 , 153 ]. There is limited research on ITO NPs for biomedical applications.…”

The Impact of the Surface Modification on Tin-Doped Indium Oxide Nanocomposite Properties

“…Nanostructured materials have applications in different fields such as energy storage, sensing, and biosensing, green chemistry, drug delivery, etc. [ 146 , 147 , 148 , 149 ]. Nanostructured ITO, due to its electrocatalytic properties, is a promising material in chemical sensors and the early-stage detection point of care biosensors [ 17 , 137 ].…”

Flexible, Transparent, and Cytocompatible Nanostructured Indium Tin Oxide Thin Films for Bio-optoelectronic Applications

“…In particular, indium tin oxide (ITO) has been employed extensively in biomedical engineering since 1985, when Gross et al described the fabrication of thin-film ITO electrodes for extracellular, multisite recording in neuronal cultures. Recent studies into ITO functionalization approaches have explored electrochemical methods to nanostructure ITO electrode surface for enhanced biocompatibility. − ITO has been morphologically modified to present surface nanorods, nanowhiskers, and nanohelixes, while retaining high conductivity and transparency for the fabrication of light-emitting diodes and solar cell technologies. Due to its high surface-to-volume ratio and biomimetic structure, it is expected that nanostructured ITO should be able to promote advantageous responses at the tissue interface, facilitating cell adhesion and electrode integration, as well as enhancing recording capacity.…”