Construction And Application Of Rapid Detection System For Dioxins Based On QCM

Quartz crystal microbalance (QCM, Quartz Crystal Microbalance) sensor has the characteristics of response to a broad spectrum, high sensitivity, and simple structure, low cost detection devices, especially as a quality-based sensors are widely used in analytical chemistry, surface chemistry, biochemistry and environmental monitoring and many other fields. Surface sensitive film is used as sensitive components in QCM sensors and the AT-cut quartz crystal as transducer elements. We use the relationship of quartz crystal quality-change frequency; transfer the quality, concentration signal into frequency. Thereby achieve the purposes of detecting the quality and concentration.The purpose of this paper is to develop sensors for detecting trace concentrations. An 8 MHz AT-cut quartz crystal resonator was modified with receptor and antibody. We have used that sensor to detect human serum albumin (HSA) and 2, 3, 7, 8-TCDD in real timeMain contents and results were as follows:Firstly, the principle, classification and application of sensors were introduced. The principle of piezoelectric quartz crystal and detection methods of dioxin were considered. We introduce a new technology to detect dioxin by using QCM.Secondly, we obtained the experimental conditions to ensure the stability of the system through many experiments on the temperature and ?ow rate, those are constant temperature and the maximum ?ow rate of 70μl/min. Finally we tested the system performance through glycerin solution of different concentrations that were 5 %、10 %、20 %、30%、40%.Thirdly, self-assembled monolayer was discoursed. The self-assembled monolayer technology and characterization methods were described. Lipoic acid was chose to form self-assembly monolayer and high insulating properties of the acidic thiol monolayer has been characterized with cyclic voltammetry and scanning electronic microscopy.Fourth, a biosensor based on a quartz crystal microbalance (QCM) was developed for dynamic and real-time detection of HSA. The frequency responses due to the adsorption of the standard samples on the biosensor surface were measured. The results show that HSA can be quantitatively detected with the developed immunosensor in the concentration range 0.1–20μg/mL. The linear equation between frequency response and HSA concentration is y = 8.8131x + 16.858 with R2=0.9945. In the range of detection, the linear relationship is satisfactory.Finally, a biosensor based on a quartz crystal microbalance (QCM) was developed for dynamic and real-time detection of 2, 3, 7, 8-TCDD. According to the principle of aryl hydrocarbon receptor (AhR) can bind dioxin. The results show that 2, 3, 7, 8-TCDD can be quantitatively detected with the developed biosensor in the concentration range 0.01–100 ng/ml. The developed QCM system offers significant improvements in speed, sample throughout and cost for the qualitative and quantitative detection of TCDD compared with GC-MS.