Cyclic voltammetric (a, c, e) and square wave voltammetric (b, d, f) responses of flavin modified standard gold electrode (a, b), porous gold flag electrode prepared of surface 1 (c, d) and porous gold flag electrode prepared of surface 2 (e, f) in 0.015 M phosphate buffer pH 6.7. Scanning performed in positive direction at a rate of 100 mV/sec.