Abstract (EN):
In this work a simple nanostructured directelectron transfer bio-electrode based on tree laccase from Rhus vernicifera is described. The electrode was implemented on a 2 mm diameter graphite mine casted with a reduced graphene surface presenting the specific capacitance of 195.8 F g(-1). About 10 mu l of mixture between 25 mg mL(-1) laccase suspension and 5 mg mL(-1) single-walled carbon nanotubes in 2% SDS is dropped over the surface followed by 5 ml of the biological friendly tetrakis (2,3-dihydroxypropyl)-silane monomer sol to provide physical entrapment in a silica matrix after gelation. The rigidity of enzyme encapsulation allowed to obtain a constant enzyme turnover of about 16 min(-1) in the extended pH range of 6.0-7.5, being the activity almost proportional to the temperature used in the interval between 25 and 40 degrees C. The graphite-graphene/SWCNTlaccase/ sol-gel electrode enabled a proportional response to molecular oxygen up to the concentration of 0.45 mmol L-1 and is capable to generate the maximum power of 4.5 mW cm(-2) at 0.250 V vs the AgCl/Ag reference electrode in quiescent oxygen saturated solution.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
7