Amperometric Detection of Dopamine based on a Graphene Oxide/PEDOT:PSS Composite Electrode

Few-layer wrinkled graphene (FLwG) has been synthesized from a coconut-shell-based charcoal using a high-voltage plasma method. Raman spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used for characterizations. Molecular dynamic simulation was also performed for further atomic/molecule movement analysis in the system. The plasma was supplied in the air gap between the electrodes. The graphite rod was used as the high voltage electrode and the aluminum plate was used as the co-electrode. The charcoal powder was arranged on the aluminum electrode surface in the air gap with a distance of ~3 cm to the graphite electrode. Raman spectroscopy analysis indicated that an FLwG had been produced. TEM analysis confirmed the presence of FLwG with a wrinkled and folded structure with an average size of 48.03 nm. XRD revealed that the produced graphene did not undergo any oxidations. Molecular dynamic simulation predicted that the FLwG formation was mainly led by the combination of ionization and deionization of air molecules under high temperatures and plasma stressing.

Section: Xrd Analysismentioning

confidence: 52%

Few-Layer Wrinkled Graphene (FLwG) Obtained from Coconut-Shell-Based Charcoal using a High-Voltage Plasma Method

Murdiya¹,

Hendri²,

Hamzah³

et al. 2022

“…The measurement shows that those various dopamine concentrations were clearly distinguishable. This could be the best candidate for a non-enzymatic dopamine biosensor (Hardi et al, 2020;Rahman et al, 2016).…”

Section: Dopamine Detection Using In Situ Measurementmentioning

confidence: 99%

Integrated Electrochemical Dopamine Sensing with Finger Priming Pump on a Chip

Whulanza¹,

Antory²,

Warjito³

et al. 2022

Development in microfluidic technology has contributed to increased understanding in neural tissue engineering through the in vitro observation of cell-on-chip (CoC) systems. This has been further helped by the integration with the broader MEMS (micro mechanical and electromechanical systems) technology that offers external devices such as detectors or biosensors to show the characteristics of the observed object. An on-chip microsystem microfluidic platform for dopamine detection is presented here. The microfluidic platform integrates electrochemical detection with finger pumping and a valve system as means to control the fluid flow. This microenvironment offers a quicker result in observing the phenomena related to the neural cell activities with a relatively small specimen volume of 50-100 µL, eases the handling of movement, and consequently reduces the cost of consumable items. The microfluidic platform presented here showed that the pump module that also serves as a mixing point was able to deliver at maximum of 121.36 µL with 2-3 strokes of normal finger pressure priming. A series of valves aids in the termination or isolation of fluid flow in a specific zone for further processing. Ultimately, the microfluidic platform is also equipped with a portable electrochemical detection module that allows us to measure the dopamine concentration up to 1 mM. This development showed that the on-chip testing of dopamine could be conducted easier and be more portable to handle.

“…Previous studies showed that multi-walled carbon nanotube (MWCNT) scaffold had good characteristics for adhesion, proliferation, and osteogenesis differentiation (Xu et al, 2019). Meanwhile, graphene-based materials and the derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), which possess high surface area and electrical conductivity (Hardi and Rahman, 2020), have also been investigated to enhance cell attachment and differentiation (Sanati et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Physical and Chemical Characterization of Collagen/Alginate/Poly(Vinyl Alcohol) Scaffold with the Addition of Multi-Walled Carbon Nanotube, Reduced Graphene Oxide, Titanium Dioxide, and Zinc Oxide Materials

Fajarani,

Rahman,

Pangesty

et al. 2024

Bone damage is one of the main causes of disability in humans, and tissue engineering technology by applying biomaterial-based scaffold has been developed as an effective solution. This can be achieved using various natural and synthetic polymers combined with carbon-based and metal-oxide materials. Therefore, this study aimed to develop bone scaffold using collagen, alginate, and poly(vinyl alcohol), with the addition of multi-walled carbon nanotube, reduced graphene oxide, titanium dioxide, and zinc oxide materials. Scaffold was fabricated with the freeze-drying method and characterized physicochemically by observing the morphology through scanning electron microscopy (SEM), identification of functional groups by Fourier transform infrared spectroscopy (FTIR), compressive mechanical properties, porosity, and degradation rate. The results showed that each group of scaffold had a compact structure, with a small pore size and less than 50% porosity. The functional groups of each material were detected, and the compressive strength matched the trabecular bone, approximately 6 MPa. However, the scaffold lacked appropriate porosity and a fast degradation rate exceeding 35% in 7 days.