Large-scale self-assembly of hydrophilic gold nanoparticles at oil/water interface and their electro-oxidation for nitric oxide in solution

Mono-/bi-layer Au nanoparticle films with large areas were prepared by the assembly of Au nanoparticles in aqueous colloid at toluene/water interfaces, which can be transferred onto the hydrophilic solid surface and adhere strongly to the substrate without any binding agent. The transferred Au nanoparticle films exhibited satisfactory catalytic performance for electro-oxidizing nitric oxide (NO) in solution, and had a low detection limit (2.7 × 10−8 mol/L), a rapid response time (less than 0.5 s) and a wide linear range (5.0 × 10−8–1.0 × 10−5 mol/L) for the detection of NO in solution. UV–vis spectra, cyclic voltammetry and chronoamperometry were conducted to characterize the prepared Au nanoparticle films.