Graphene-Au composite sensor for electrochemical detection of para-nitrophenol

A novel electrochemical sensor for para-nitrophenol (p-NP) was constructed with graphene-Au composite containing 10 % Au (G-Au 10 %). In the composite, Au nanoparticles with the size of ca. 11 nm were regularly scattered on graphene sheet without aggregation, which offers dramatically higher electrocatalytic activity on the redox of K-3[Fe(CN)(6)]/K-4[Fe(CN)(6)] couple than sole Au nanoparticles. Compared to sole Au nanoparticles, the G-Au 10 % also exhibited dramatically improved electrocatalytic activity on the reduction of p-NP. Amperometric detection of p-NP at G-Au 10 % modified electrode displayed a wide linear range of 0.47-10.75 mM with detection limit of 0.47 mu M and a high sensitivity of 52.85 mu A/mM. Considering the thrifty in utilization of noble Au, the G-Au 10 % can be successfully applied as a low-cost and powerful sensing material for trace detection of p-NP.