Synthesis of starch-stabilized silver nanoparticles and their application as a surface plasmon resonance-based sensor of hydrogen peroxide

Stable and uniform starch-stabilized silver nanoparticles with average diameter 14.4 +/- 3.3 nm are synthesized via green synthetic procedure, using ultrasound mediated reduction of silver nitrate by D-glucose. UV-vis spectroscopy, high-resolution transmission electron microscopy, X-ray diffraction, thermogravimetric/differential thermal analysis and differential scanning calorimetry are used to completely characterize the starch-stabilized silver nanoparticles. These nanoparticles exhibit a catalytic activity in the reduction of hydrogen peroxide (H2O2). The degradation of silver nanoparticles, induced by the catalytic decomposition of hydrogen peroxide, causes a considerable change in the absorbance strength of localized surface plasmon resonance band depending on the H2O2 concentration. The characterization and calibration of improvised plasmon resonance-based optical sensor is carried out. A good sensitivity and a linear response over the wide concentration range of 10(-1)-10(-6) mol/L H2O2 is established. The quantification limit of this sensor is found to be 0.9 mu M H2O2, which is lower than certain enzyme-based biosensors. Therefore, this optical sensor for hydrogen peroxide can be potentially applied in determination of other reactive oxygen species as well. (C) 2010 Elsevier B.V. All rights reserved.