This paper demonstrates local pH measurement in a microchip using a pH-sensing gel-microbead. To achieve this, the gel-microbead made of a hydrophilic photo-crosslinkable resin was functionalized with the pH indicator bromothymol blue (BTB). The primary constituent of this photo-crosslinkable resin is poly(ethylene glycol). Gel-microbeads impregnated with BTB were obtained by stirring the mixtu...

Shigella species are generally considered to be unable to ferment salicin (Breed, Murray, and Smith, Bergey's Manual of Determinative Bacteriology, The Williams & Wilkins Co., Baltimore, 1957; Kauffmann, Enterobacteriaceae, E. Munksgaard, Copenhagen, 1950; Edwards and Ewing, Identification of Enterobacteriaceae, Burgess Publishing Co., Minneapolis, 1955). Recently, however, Ser6ny (Acta Microbi...

pH-Sensitive dyes are increasingly applied on polymer substrates for the creation of novel sensor materials. Recently, these dye molecules were modified to form a covalent bond with the polymer host. This had a large influence on the pH-sensitive properties, in particular on the acidity constant (pKa ). Obtaining molecular control over the factors that influence the pKa value is mandatory for t...