Colorimetric determination of hydrogen peroxide by morphological decomposition of silver nanoprisms coupled with chromaticity analysis

A novel colorimetric method with image colour analysis for highly sensitive and accurate detection of hydrogen peroxide using starch-stabilized silver nanoprisms (AgNPrs) is proposed. AgNPrs were morphologically decomposed by a low concentration of hydrogen peroxide revealed by UV-visible absorption spectroscopy and transmission electron microscopy (TEM). The morphological changes of AgNPrs led to an appreciable colour change in the AgNPr solution from red to orange, and finally yellow. A good linear relationship between the wavelength shift of AgNPrs and the H2O2 concentration can be obtained. The solution phase detection of H2O2 by the direct morphological change can be accomplished without any surface modification of AgNPrs. In addition to the conventional determination of the H2O2 concentration utilizing spectroscopic data, a new and simple colorimetric strategy based on the chromaticity analysis of AgNPr solution was demonstrated. The strategy can be employed not only for visual detection of H2O2 by the naked eye but also for reliable and convenient methods for quantification of H2O2. The hydrogen peroxide concentration at 1.57 mu M can be recognized by naked-eye observation with good accuracy, stability and reproducibility. Furthermore, the proposed protocol can be applied to determine the glucose concentration through the glucose-oxidase system. A good linearity between the red chromaticity of the solution colour and the glucose concentrations was observed. The new colorimetric determination of hydrogen peroxide utilizing digital image analysis on colour changes from AgNPr shape decomposition will open up an alternative method for simple, rapid and reliable detection of hydrogen peroxide and can realize its future applications in biochemical analysis or clinical diagnosis.