Abstract:Graphene-based butyrylcholinesterase biosensors were prepared utilizing chitosan (CS) and graphene nanosheets (GS) composites to immobilized butyrylcholinesterase (BuChE) on the glass carbon electrode by crosslinking technology, the rapid and sensitive method for the determination of malachite Green (MG) in sea foods was developed. Effects of biosensor modified materials, electrolyte solution, enzyme activity and inhibition time on response current of enzyme biosensor were investigated. The optimum analytical parameters for determination of Malachite Green were determined as follows:the ratio of CS to GS was 1:2, the electrolyte solution was 0.1 mol/L PBS, the pH was 7, the inhibition time was 11 min, and the enzyme activity was 4.0 U/mL. Under optimum conditions, the response currents of the enzyme biosensor had a good linear relationship with MG concentration with a detection range from 1.00×10-7 mol/L to 1.10×10-6 mol/L. The linear equation was Ip=-6.97CMG+22.805 (R2=0.9885), with the limit of detection (LOD) as 2.80×10-8 mol/L (S/N=3). The addition standard recovery of the developed method was 96.36% to 99.78%. The developed method is simple, rapid and sensitive with good selectivity and excellent repeatability, which is practicable for rapid determination of MG or LMG in sea foods.
