Resumo de eventos cient??ficos
Reduced graphene oxide obtained by gamma radiation to produce screen printed glucose biosensor
Registro en:
0000-0001-6072-5853
Autor
SAKATA, SOLANGE
JACOVONE, RAYNARA M.S.
DUARTE, MIGUEL
GARCIA, RAFAEL
ANGNES, LUCIO
INTERNATIONAL CONFERENCE ON APPLICATIONS OF RADIATION SCIENCE AND TECHNOLOGY, 2nd
Resumen
Screen printed biosensor has attracted attention as point care device due to its fast and
accurate response in a compact portable platform. Due the high electrical carrier mobility, reduced graphene
oxide (rGO) has been used to modify the working electrode surface and increase the biosensor sensibility.
However, there are some disadvantages during the reduction of graphene oxide that include the use of chemical
reductants that need to be removed after the reaction and the toxic residues. The purification usually
requires tedious steps and a lot of efforts to recover the nanomaterial. In this work screen printed carbon
electrode (SPCE) was modified using rGO produced by gamma radiation. Graphene oxide (GO) was prepared
by modified Hummers and the reduction was performed in a water/isopropanol solution and inert medium.
Sample was irradiated in the Multipurpose Gamma Irradiation Facility at Radiation Technology Center from
Nuclear and Energy Research Institute (IPEN/CNEN-SP), a category IV gamma irradiator by the IAEA classification
under the radiation dose at 80,0 kGy. rGO characterization was performed by X-Ray Diffraction
(XRD). From the XRD patterns: the 2?? the peak located at 11o shift to 23o, demonstrating the reduction of GO
to rGO. The decrease of the distance between layers was attributed on partial remove of the oxygen groups
from GO. For the glucose biosensor preparation, first of all, the SPCE (Metrohm, model 6. 1208. 110) was
modified by drop-coating rGO solution and dried at room temperature for 24h. Then, for Glucose Oxidase
(GOx) immobilization, the carboxylic groups from rGO were activated using N-hydroxysuccinimide (NHS)
and 1-Ethyl-3-(3-dimethyalaminopropyl) carbodiimide (EDC) for 30 min at room temperature, followed by
adding GOx 10KU from A. niger Type II (5mg/mL). The solution was incubated at 4oC overnight. SEM images
showed GOx onto SPCE surface and the electrocatalysis of GOx toward glucose was measured to confirm the
enzymatic activity. For electrochemical studies, cyclic voltammetry was carried out in a Portable Potentiostat
model 910 PSTAT mini, Metrohm and PSTAT software. The fabricated amperiometric biosensor detects glucose
ranged from 1mM to 5mM with LOD of 0.9 mM at 0.70V. Moreover, the biosensor exhibited repeatability,
reproducibility and practicability.
This study showed that rGO synthesized by gamma radiation without any further purification is a simple and
sustainable approach to fabricate electrode for biosensors.