Layer-by-layer self-assembly of multilayer films of polyelectrolyte/Ag nanoparticles for enzymeless hydrogen peroxide detection

In the paper, we report on the layer-by-layer self-assembly of multilayer films of polyelectrolyte/Ag nanoparticles (AgNPs). The films were constructed by the alternate adsorption of the oppositely charged poly [(2-ethyldimethylammonioethyl methacrylate ethyl sulfate)-co-(1-vinylpyrrolidone)] (PQ11) and negatively charged citrate-stabilized AgNPs on solid substrates. The multilayer film growth process on quartz slides was monitored by UV-vis absorption spectroscopy. The resulting films exhibit good catalytic activity toward the reduction of hydrogen peroxide (H2O2). The enzymeless H2O2 sensor based on such films exhibits a fast amperometric response time of less than 5 s. The linear detection range is estimated to be from 100 μM to 110 mM (R2 = 0.996), and the detection limit is estimated to be 78 μM at a signal-to-noise ratio of 3.