Showing papers by "Shouzhuo Yao published in 1996"
TL;DR: A technique using a quartz crystal microbalance sensor coated with a thin culture medium film was developed and successfully applied to determine the number of Staphylococcus epidermidis in the range of 1 × 102 −4.1 × 107 cells ml−1, based on a good linear relationship between the turning point time and the number.
64 citations
TL;DR: In this paper, a method based on the response of a thickness shear mode sensor to electrocapillary phenomena for determination of the potential of zero charge at solid metal (solution interfaces) is described.
20 citations
TL;DR: In this paper, a simple, rapid, on-line quartz crystal sensor is proposed for monitoring viscosity changes in culture medium caused by microbe growth, and a model based on frequency response of the crystal to microbe growing is presented.
19 citations
TL;DR: The proposed SAW urea sensor has been successfully applied to the rapid determination of urea in human urine samples and also support the clinical diagnosis.
15 citations
TL;DR: The use of a series piezoelectric crystal (SPC) device for the preparation of biosensors has been investigated in this paper, where the urease sensor exhibits favorable frequency response to 1 x 10−5-3x10−3 M urea with a response time of ca3 min.
Abstract: The use of a series piezoelectric crystal (SPC) device for the preparation of biosensors has been investigated These biosensors are fabricated by mounting the immobilized urease layer or the jack bean tissue slices on the probe surfaces of the SPC ammonia sensor The urease sensor exhibits favourable frequency response to 1 x 10−5-3x10−3 M urea with a response time of ca3 min Dynamic range, reproducibility, response time and selectivity of the sensors are discussed Results show the SPC is an attractive alternative internal sensing element to develop biosensing devices The urease sensor has been used successfully for the determination of urea in serum samples; the results are comparable to those from a spectrophotometric method On leave from Hengyang Medical College, Hunan, 421001, China
14 citations
TL;DR: The SAW-IDA sensor offers a new and effective way of studying clinical and laboratory haemostasis and was applied to determination of recalcification time and activated partial thromboplastin time of blood plasma.
13 citations
TL;DR: The SPQC-based BAW detector as mentioned in this paper has been used in inorganic, organic, and bio-medical analysis and its applications are summarized in detail in the present paper.
Abstract: BAW-based detectors can be divided into two classes: mass-effect-based and non-mass-effect-based BAW detectors. Only the non-mass-effect-based BAW detectors give satisfactory performance in eluent monitoring. Detector design and operation principle of the SPQC-BAW detector are described in detail in the present paper. Its applications in inorganic, organic and bio-medical analysis are summarized.
13 citations
TL;DR: In this article, a surface acoustic wave (SAW) enzyme sensor system has been applied to the assay of extracted lipase activity based on triacetin solution as substrate, and a linear relationship between the frequency change and the enzyme activity up to 500 U/L has been obtained, and the detection limit has been evaluated to 0.3 U /L.
Abstract: A new kind of surface acoustic wave (SAW) enzyme sensor system has been applied to the assay of extracted lipase activity based on triacetin solution as substrate. A linear relationship between the frequency change and the enzyme activity up to 500 U/L has been obtained, and the detection limit has been evaluated to 0.3 U/L. Kinetic parameters of the extracted lipase as well as that of the standard enzyme have been estimated. The effects of temperature, pH value and surfactants have been investigated. A comparison between SAW sensor system and the conductometric method has been carried out. The technique has been applied to the determination of lipase activity in serum samples.
8 citations
TL;DR: Antitrypsin in human serum was determined by using both the SAW-impedance sensor system and spectrophotometry, indicating that themean value for women was significantly higher than the mean value for men.
Abstract: Antitrypsin in human serum was determined by using both the SAW-impedance sensor system and spectrophotometry, indicating that the mean value for women was significantly higher than the mean value for men; the value for acute pancreasis patients is about 2-folds of the normal values, and there is no significant difference between the acute pancreasis patients and the pancreatic cancer patients.
7 citations
TL;DR: In this paper, a piezoelectric quartz crystal sensor (PQC) coated with a thin liquid culture medium film was developed and applied to detect the cell number of Proteus vulgaris.
6 citations
TL;DR: A simple and sensitive extraction-gravimetric method based on the extraction of free dipyridamole with chloroform, after neutralization with a basic agent, followed by measurement of the frequency shift response of the specially designed surface acoustic wave resonator sensor after evaporation of the extractant from the surface of the resonator.
TL;DR: In this paper, the authors studied the possibility of continuously on-line measuring the growth of Salmonella typhimurium on solid medium, which is not only suitable for isolation and identification of Gram-negative intestinal bacilli but also fit for monitoring bacteria with a thickness shear mode acoustic resonator in series.
TL;DR: The proposed piezoelectric crystal impedance sensor has been used successfully for lamp sulphur determinations in petroleum samples and exhibits a favourable frequency response to 1 x 10 (-7)-1 x 10(-3) M sulphur dioxide.
TL;DR: In this article, a novel bulk acoustic wave (BAW) sensor for the detection of dissolved ammonia can be realized by using a new BAW device, in which an AT-cut piezoelectric crystal is connected in series with a probe.
TL;DR: A thickness shear mode bulk acoustic wave sensor coated with a thin liquid culture medium film was developed and applied and demonstrated that there was a good linear relationship between the turning point time and the logarithm of the P. mirabilis concentration.
TL;DR: An extended set of equations which describe coupled arginase-urease reactions is presented, which relate the lag-time required for the concentration of urea to reach a defined fraction of its steady-state concentration to the kinetic parameters of the enzymes.
TL;DR: In this article, a surface acoustic wave (SAW) sensor system was used to extract urease from plant seeds and the kinetic frequency response, the Urease activity, Michaelis constants and other kinetic parameters were measured by means of a new device, i.e., a SAW sensor system, which was composed of a 61 MHz SAW resonator and a pair of parallel platinum electrodes.
Abstract: Urease was extracted from several kinds of plant seeds and the kinetic frequency response, the urease activity, Michaelis constants and other kinetic parameters were measured by means of a new device, i.e. a surface acoustic wave (SAW) enzyme sensor system, which was composed of a 61 MHz SAW resonator and a pair of parallel platinum electrodes. Influences such as extracting conditions, pH and temperature and the specificity were also investigated. The method has been successfully applied in the clinical assay of urea in human urine and blood. The results are in agreement with the reported values and also support the clinical diagnosis.
TL;DR: In this article, a method based on the inhibition of the lipase-catalyzed hydrolysis by binding hydroxyl groups of lipase with organophosphorus pesticide is described for the enzymatic determination of organic compounds.
Abstract: A convenient and sensitive method based on the inhibition of the lipase-catalyzed hydrolysis by binding hydroxyl groups of lipase with organophosphorus pesticide is described for the enzymatic determination of organophosphorus pesticides. Employing the method proposed, the frequency response is proportional to organophosphorus pesticide concentration over the range of 250 ng/ml∼1.25 μg/ml. the detection limit is 58 ng/ml. The effects of temperature, pH value, incubation time and solvent are also investigated.
TL;DR: In this paper, a surface acoustic wave (SAW)/impedance sensor system in electrolyte solution is presented, which is constructed by a 62-MHz SAW resonator and a pair of conductive electrodes in series.
TL;DR: A non-linear regression model was derived for the simultaneous determination of the rate constant in alkaline hydrolysis of esters and the initial concentration of ester based on the linear relationship between the frequency response of the surface acoustic wave sensor system and the conductivity of the solution.
TL;DR: An impedance sensor for the determination of nitrogen oxide in aqueous solution is presented in this paper, which is realized by using a series piezoelectric crystal (SPC) device.
Abstract: An impedance sensor for the determination of nitrogen oxide in aqueous solution is presented. The sensor is realized by using a series piezoelectric crystal (SPC) device, which is constructed by connecting an AT-cut piezoelectric crystal with a probe in series. The probe is filled with an internal electrolyte solution that is separated from sample solutions by a gas-permeable membrane. Such a gas sensor based on the SPC device can overcome the influence of water vapour efficiently and can be used in the determination of nitrite in aqueous solutions. The proposed sensor exhibits a favourable frequency response to 5 × 10–7–1 × 10–3 mol l–1 nitrite. The limit of detection is 1 × 10–7 mol l–1. Aspects of the sensor preparation are considered. The dynamic range, reproducibility, response time and selectivity of the sensor are also discussed. The proposed sensor was used successfully for the determination of nitrite in smoked pork samples; the results obtained were comparable to those obtained by the official first action AOAC method. The technique described here should find wider application in the development of other gas and enzyme sensors.