Synthesis of Ultrastable Ag Nanoplates/Polyethylenimine-Reduced Graphene Oxide and Its Application as a Versatile Electrochemical Sensor.

Investigations on Ag nanostructures/reduced graphene oxide composites have been frequently reported, yet the morphology control of those loaded Ag nanocrystals is still challenging. We herein develop a facile method to grow triangular Ag nanoplates (AgP) on polyethylenimine-modified reduced graphene oxide (AgP/PEI-rGO). The AgP/PEI-rGO hybrids show unexpected high stability against chloride ions (Cl−) and hydrogen peroxide (H2O2), which is possibly due to the strong interaction between surface Ag atoms with the amine groups of PEI. In the chronoamperometry measurements for detecting H2O2, N2H4, and NaNO2, the AgP/PEI-rGO hybrid shows very wide linear ranges (usually 10−6-10−2 mol L−1 for H2O2, N2H4, and NaNO2) and low detection limits (down to ≈1×10−7 mol L−1), which demonstrate the promising electrochemical sensor applications of these metal/graphene hybrids with well-defined morphologies and facets. In addition, this strategy could be extended to the deposition of other noble metals on rGO with controlled morphologies. [ABSTRACT FROM AUTHOR]