A wireless pH sensor based on the use of salt-independent micro-scale polymer spheres
2003; Elsevier BV; Volume: 96; Issue: 1-2 Linguagem: Inglês
10.1016/s0925-4005(03)00486-6
ISSN1873-3077
AutoresChuanmin Ruan, Keat Ghee Ong, Casey Mungle, Maggie Paulose, Nicholas Nickl, Craig A. Grimes,
Tópico(s)Acoustic Wave Resonator Technologies
ResumoPoly(vinylbenzylchloride-co-2,4,5-trichlorophenyl acrylate) (VBC-TCPA) spheres, approximately 725 nm in diameter, were prepared by dispersion polymerization then derivatized with diethanolamine to realize a mass changing pH-responsive polymer. While the pH-responsive polymer spheres are suitable for use with any mass-sensitive sensor platform, in this work, the polymer spheres are combined with magnetoelastic thick films to achieve a remote query pH sensor. The magnetoelastic pH sensors were fabricated by spin-coating the aminated polymer spheres onto the surface of a magnetoelastic ribbon. The pH response of these sensors was examined by monitoring changes in sensor resonance frequency as a function of test-solution pH. The sensors demonstrate a linear pH response from pH 3.0 to 9.0, with a change in resonance frequency fr of 0.2% fr per pH for a 1.5-μm thick polymer layer. Measurements were virtually independent of background potassium chloride concentration.
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