Title : Fabrication of flash graphene-enhanced gan for surface acoustic waves biosensor applications
Abstract:
New, accurate, and fast biosensors of viruses are being studied as an effort to prevent future virus outbreaks. Although conventional diagnostic methods have been adopted and succeeded, they show drawbacks including lengthy data analyses, high costs and low sensitivity. Graphene-enhanced GaN has the potential to give rise to surface acoustic waves (SAW) biosensors with high sensitivity and accuracy for virus detection, in addition to the possibility of being produced using cheaper and faster routes. Hence, GaN thin film was grown on silicon substrates by reactive sputtering technique to serve as a high acoustic speed piezoelectric base material. After that, boron-doped and undoped graphene powders were synthesized by the flash Joule heating method. The doped and undoped flash graphene (FG) powders were used to produce an electrically conductive coating with satisfactory adhesive properties atop the GaN surface. The GaN thin film, and the doped and undoped FG powders were characterized by Raman, X-ray diffractometry, and X- ray photoelectron spectroscopy. Additionally, the FG/GaN heterojunction was characterized by two-point probe system and nanoindentation. The sputtered GaN thin film had a preferential c-orientation nanocrystalline wurtzite structure. The FG powders exhibited graphene content of 100% with ~1.6% boron doping. The obtained graphene coatings are stable, with conductivity ranging from a few k? to G?, controlled by the concentration ratio by weight of graphene and a polymeric binder. Therefore, preliminary FG/GaN heterojunctions were successfully produced and are being optimized to produce functional SAW biosensors, as evaluated by the frequency response on a network analyzer.
Audience Take Away:
- They will learn how to use optimized conditions to grow GaN on cheap and wide use Si wafers. They will be able to produce a graphene slurry with high concentration of graphene and how to increase the conductivity by changing the ratio concentration between graphene and binder, as well as, by using boron doped graphene to it. By the end, they will learn how to make a good adhesion of this ink in the substrate and what are the prospects of this material.
- Using analytical thinking and characterizations techniques to assure the success of the synthesis.
