Facile fabrication of hierarchical nanoporous AuAg alloy and its highly sensitive detection towards dopamine and uric acid

Hierarchical nanoporous AuAg (HNP-AuAg) alloy with bimodal ligament/pore size distributions is fabricated by means of selective dealloying of Al and redealloying of Ag from AuAgAl source alloy combined with annealing operation. The as-made HNP-AuAg alloy consists of interconnected hierarchical nanoporous architecture with two order ligament/pore size distributions around 100 and 10 nm in all three dimensions. Characterized by such the specific nanoporous architecture, HNP-AuAg alloy exhibits excellent electrocatalytic activities towards the simultaneous and individual oxidation of dopamine (DA) and uric acid (UA) in the absence and presence of ascorbic acid. The electrochemical sensing towards DA and UA on HNP-AuAg alloy displays fast response and low detection limit of 0.2 mu M and 1.0 mu M in a wide linear range of 5-335 mu M and 5-425 mu M, respectively. More importantly, the as-made HNP-AuAg alloy behaves long-term stability and reproducibility towards the detection of DA and UA. Along with these attractive features, HNP-AuAg shows great application potential for constructing electrochemical sensors to the detection of DA and UA. (C) 2015 Elsevier B.V. All rights reserved.