In this study, the electrodes inserted into a measuring cell were seriated with an oscillating circuit to construct a series piezoelectric quartz crystal (SPQC) system. Over the measuring range (15 to 6610 μS), the response of oscillating frequency (f) would descend firstly with respect to the increase of solution conductivity (δ) and then change to ascent again for higher conductivity. We found that there was a relatively higher sensitivity (56 Hz/μS)of the SPQC system between 1 and 3 mS. To assess the reliability for the home-made SPQC system, we introduced it for the test of acid-base and precipitation titration and obtained the recovery rates at 98.4 % and 99.0 %, respectively. The SPQC system was also applied for a biochemical assay. As a result, the frequency detection time (FDT) for Escherichia coli (E. coli) could be clearly defined and concluded a linear relationship (from 410 min to 80 min) in one milliliter of medium that contained colony forming unit (CFU) from 10 to 107.
|Number of pages||8|
|Journal||Chinese Journal of Medical and Biological Engineering|
|Publication status||Published - 1997 Dec 1|
All Science Journal Classification (ASJC) codes