Poly(vinyl alcohol) capped silver nanoparticles as localized surface plasmon resonance-based hydrogen peroxide sensor

摘要

A colorimetric hydrogen peroxide sensor based on localized surface plasmon resonance of poly(vinyl alcohol) capped silver nanoparticles is introduced. The silver nanoparticles are directly synthesized in the PVA matrix by a one-step method based on the reduction of the inorganic precursor AgNO_3 through thermal treatment in aqueous medium. No other reagent is used. These nanoparticles are characterized using UV-vis spectroscopy, transmission electron microscopy and X-ray diffraction. Then they are used for the preparation, characterization and calibration of a highly sensitive, cost-effective and renewable localized surface plasmon resonance-based hydrogen peroxide sensor. The silver nanoparticles have the catalytic ability for the decomposition of hydrogen peroxide; then the decomposition of hydrogen peroxide induces the degradation of silver nanoparticles. Hence, a remarkable change in the localized surface plasmon resonance absorbance strength could be observed. As a result, the yellow colour of the silver nanoparticle-polymer solution was gradually changed to transparent colour. Furthermore, when this transparent solution was subjected to thermal treatment, it became again yellow and the UV-vis spectroscopy confirmed that nanoparticles were again formed, suggesting the renewability of this sensor. The determination of reactive oxygen species such as hydrogen peroxide has possibilities for applying to medical and environmental applications.