Photoelectrochemical Performance of Brookite Titanium Dioxide Electrodeposited on Graphene Foam for Portable Biosensors
Highlights
- This work presents the electrosynthesis of a photoactive TiO2 pohase on Gii without the need for thermal annealing.
- Approximately 2.1x the value for traditional carbon-based printed electrodes was achieved by using Gii instead of a carbon-based electrode.
Abstract
We discuss the photoelectroanalytical performance of a brookite-phase titanium dioxide (TiO2) platform electrodeposited onto graphene foam (GF) at low temperatures.
The scalable electrosynthesis process eliminates the need for thermal annealing, which is impractical for carbon-based electrodes.
Films resulting from a 10 min electrodeposition (TiO2-10/GF) exhibit enhanced photocurrents, reaching 170μAcm−2 GEO-twice the value for TiO2 films on traditional screen-printed carbon electrodes (82 μA cm−2 GEO).
The increased photocurrent density makes TiO2-10/GF ideal for on-site photoelectrochemical biosensors as it allows for compact systems with low-power LEDs.
Introduction
Photoelectrochemical (PEC) sensors show potential for clinical diagnostics and environmental monitoring, offering low detection limits by minimizing background signals. This is possible owing to the separation between the readout source and the excitation source, which, in this case, is light.[1]
The miniaturization and cost reduction of these devices require the use of compact light sources, printed electrodes, and photoactive nanomaterials that operate with low-power irradiation.[2]
Titanium dioxide (TiO2) is used in PEC analysis due to its photoactivity, cost-effectiveness, photostability, biocompatibility, and low toxicity.[3] TiO2 exists in three main crystal structures: anatase, which is stable at low temperatures; brookite, typically found in minerals but challenging to synthesize; and rutile, which is stable at higher temperatures.[4]
Platforms with enhanced photoactivity have been reportedby combining TiO2 with graphene-based materials. These composites offer large specific surface areas and improved conductivity, making them ideal for photocatalysis applications.