An acoustic wave sensor for the hydrophilic fluoride

作者：Valente Nuno I P; Muteto Paulino V; Farinha Andreia S F; Tome Augusto C; Oliveira Joao A B P; Gomes M Teresa S R^*

来源：Sensors and Actuators B: Chemical , 2011, 157(2): 594-599.

DOI：10.1016/j.snb.2011.05.028

• Acoustic wave sensor
• Fluoride
• Calix[4]pyrrole
• Piezoelectric quartz crystal

A new acoustic wave sensor to detect and quantify fluoride, one of the most hydrophilic anions, is proposed. Meso-octamethylcalix[4]pyrrole (OMCP) and seven of its derivatives were evaluated as piezoelectric quartz crystal coatings. Some of these sensors experienced appreciable coating leaching under a water flow, while others did show a very small sensitivity to fluoride. As the OMCP-naphthoquinone sensor was very sensitive to fluoride and did not lose a significant amount (alpha = 0.05) of coating during eight weeks, it was selected among all the others. A piezoelectric crystal coated with an amount of OMCP-naphthoquinone that produced a frequency decrease of 22 kHz showed a linear calibration range that extended up to 80 mg L(-1), within which sensitivity to fluoride was 0.45 Hz L mg(-1), and was able to detect fluoride at the concentration of 3.66 mg L(-1). This sensor was used to determine fluoride in commercial fluoride tablets, and the result found was not statistically different (alpha = 0.05) from the value provided by the manufacturer.

• 出版日期2011-10-20