Two-dimensional graphene paper supported flexible enzymatic fuel cells.
Fei ShenDmitrii PankratovArnab HalderXinxin XiaoMiguel D ToscanoJingdong ZhangJens UlstrupLo GortonQijin ChiPublished in: Nanoscale advances (2019)
Application of enzymatic biofuel cells (EBFCs) in wearable or implantable biomedical devices requires flexible and biocompatible electrode materials. To this end, freestanding and low-cost graphene paper is emerging among the most promising support materials. In this work, we have exploited the potential of using graphene paper with a two-dimensional active surface (2D-GP) as a carrier for enzyme immobilization to fabricate EBFCs, representing the first case of flexible graphene papers directly used in EBFCs. The 2D-GP electrodes were prepared via the assembly of graphene oxide (GO) nanosheets into a paper-like architecture, followed by reduction to form layered and cross-linked networks with good mechanical strength, high conductivity and little dependence on the degree of mechanical bending. 2D-GP electrodes served as both a current collector and an enzyme loading substrate that can be used directly as a bioanode and biocathode. Pyrroloquinoline quinone dependent glucose dehydrogenase (PQQ-GDH) and bilirubin oxidase (BOx) adsorbed on the 2D-GP electrodes both retain their biocatalytic activities. Electron transfer (ET) at the bioanode required Meldola blue (MB) as an ET mediator to shuttle electrons between PQQ-GDH and the electrode, but direct electron transfer (DET) at the biocathode was achieved. The resulting glucose/oxygen EBFC displayed a notable mechanical flexibility, with a wide open circuit voltage range up to 0.665 V and a maximum power density of approximately 4 μW cm -2 both fully competitive with reported values for related EBFCs, and with mechanical flexibility and facile enzyme immobilization as novel merits.
Keyphrases
- carbon nanotubes
- electron transfer
- reduced graphene oxide
- solid state
- induced apoptosis
- low cost
- cell cycle arrest
- room temperature
- hydrogen peroxide
- gold nanoparticles
- blood glucose
- quantum dots
- walled carbon nanotubes
- cell death
- metabolic syndrome
- signaling pathway
- type diabetes
- transcription factor
- minimally invasive
- weight loss
- human health
- insulin resistance
- transition metal
- amino acid