Construction of Cu2O-Ag Nanocomposites for the Selective and Efficient Electrochemical Detection of Catechol

Highly sensitive and selective electrochemical sensors are essential for human health, especially for monitoring the state of environmental pollutant content. Here, Cu2O nanocubes uniformly decorated with Ag nanoparticles were synthesized by a tractable wet-chemical method. The electrochemical studies confirm that the Cu2O-Ag-16 composite shows increased electrochemical activity for catechol determination compared with either the bare Cu2O or the other two as-proposed Cu2O Ag catalysts (Cu2O Ag-8, Cu2O Ag-24). More specifically, the Cu2O Ag-16 presents excellent electrochemical responses towards catechol detection over wide linear ranges of 0.05 mu M - 1 mM and 1 mM - 5 mM, with high sensitivity and low detection limits (50 nM). Furthermore, the as-proposed sensor also displays good reproducibility, with a relative standard deviation of 2.3% (n= 3). Satisfactory recoveries in the range of 98.3% to 101.2% or 98% to 100.7% for lake water and/or tap water indicate the reliability of the sensor for catechol detection in practical applications. Constructing such composite structures to manipulate the local charge distribution for outstanding electrochemical sensing properties would provide us with an innovative strategy to explore other highly efficient electrode materials.