Crown-ether containing copolymers as selective membranes for quartz crystal microbalance chemical sensors

✍ Scribed by Philip L Drake; Gareth J Price

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 105 KB
• Volume: 49
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/1097-0126(200009)49:9<926::aid-pi378>3.0.co;2-h

✦ Synopsis

Novel chemical sensors have been developed based on piezoelectric quartz resonators coated with chemically engineered copolymer resins. These have been employed for the selective detection in aqueous solution of K over other Group I ions such as Li and Na .

A quartz crystal microbalance, QCM, operating with 10 MHz, AT-cut piezoelectric crystals and Au electrodes, forms the basis of the sensor set-up where the frequency changes indicate a change in absorbed mass of the species of interest. The copolymer coating was designed to chelate speci®c ions from solution introducing selectivity to the sensor response. Acrylic acid polymers crosslinked with ethylene glycol dimethacrylate (EGDMA) and substituted with 18-crown-6 and the 15-crown-5 rings were synthesized and coated onto the crystal. The sensor was employed in a ¯ow injection analysis (FIA) set-up. The detection limit of the developed sensor is estimated at 0.4 ppm for K aq , although further optimization should signi®cantly reduce this value.