Piezoelectric Quartz Crystal Sensor Technology In Life Science Research And Applications

Piezoelectric quartz crystal (PQC) sensor, capable of yielding abundant information by detecting the interaction between the sensor and target components, has found its extensive applications in various fields such as analytical chemistry, biology, membrane science, biochemistry, clinical medicine and environmental science. A brief review is given on the latest development of PQC sensor and its application in gas/liquid analysis. Efforts have been made in the present thesis.The studies made in the thesis are summarized as follows:1. A series piezoelectric quartz crystal (SPQC) sensor has been applied to detect L-glutamic acid and L-lysine. The effect of formaldehyde on the frequency shift was studied. Two methods were discussed. For the calibration curve method, in a neutralized formaldehyde medium, the linear ranges for determining L-glutamic acid and L-lysine were from 7.1×10-6 M to 6.5×10-4 M and from 6.9×10~6 M to 7.4×10~4 M respectively, with the detection limits being 7.1× 10-6 M and 6.9×10-6 M. The recoveries were 99.2% and 100.1%, the R.S.D were 1.63% (n=6) and 1.83%(n=6), respectively. Frequencimetric tiration method was also described and the lowest titratable concentrations were 8.3×10-5M and 5.5×10-5 M, respectively.2. Piezoelectric quartz crystal impedance (QCI) technique was first used for monitoring the process of Cu2+-induced precipitation ofbovine serum albumin onto the gold electrode and applied to these assay (1) In situ monitoring the precipitation process of bovine serum albumin using QCI technique. (2) The bovine serum albumin (BSA) was determined by QCI technique through the precipitation of BSA with Cu24. The linear range for determining BSA was from 4x10" g/L to 4×10-1 g/L, with the detection limit being 1.9×10-4 g/L. The recovery was 101.4%; the R.S.D was 3.7% (n=6). The effects of low molecular weight alcohol and pH have been investigated. (3) The dynamic process of bovine serum albumin (BSA), Cu2+ and EDTA combination was monitored by using piezoelectric quartz crystal impedance (QCI) technique. The reaction rate constant between BSA and Cu2+ was detected, i.e., k = 0.01s-1, and that between BSA-Cu2+ and EDTA was 0.08s-1. The relationship between the response of the resonant frequency and the EDTA concentration was discussed, and the linear equation was found to be Δf = 5857.cEDTA-1047.3, r=0.9993...