The development of an optical pH sensor based on immobilization of quinizarin (1,4-dihydroxyanthraquinone) on a triacetylcellulose membrane was described. The resulting membrane exhibited fast color change from yellow to violet, while changing the pH in alkaline region. The immobilized quinizarin showed a broader dynamic range from (pH 9.4-11.4) with respect to free form (pH 8.8-10.4). The sens...

We report the development of a scanning force microscope based on an ultra-sensitive silicon nitride membrane transducer. Our is made possible by inverting standard geometry - in our instrument, substrate vibrating and tip at rest. present first topography images samples placed surface. measurements demonstrate that retains excellent sensitivity when loaded with presence tip. discuss prospects ...