Electrochemical determination of nepafenac topically applied nonsteroidal anti-inflammatory drug using graphene nanoplatelets-carbon nanofibers modified glassy carbon electrode

Nepafenac is novel ophthalmic agents with a unique prodrug structure and superior corneal permeability to other currently available topical nonsteroidal anti-inflammatory drugs. A graphene nanoplatelets and carbon nanofibers modified glassy carbon electrode was developed and used as first electrochemical sensor for the determination of nepafenac. The effective combination of graphene and carbon nanofibers resulted in electrochemical sensor with large surface area, high sensitivity, good stability and selectivity. After method optimization, the square wave voltammograms, at a preconcentration time of 60 s, display two linear ranges of 4.0 x 10(-6)-1.5 x 10(-5) M and 2.5 x 10(-7)-4.0 x 10(-6) M for drug quantification with a detection limit of 6.3 x 10 -8 M. The modified electrode was employed for fast assay of nepafenac in ophthalmic solution with satisfactory results and rapid run time of 66 s in comparison with previously reported analytical methods.