Design Of Micro-channel Systems And A Bioanalyzer Based On Optical Surface Plasman Resonance

Surface plasman resonance biosensors are an interdisciplinary technology which involves optical engineering, mechanical engineering, electronic engineering and biochemical engineering. It provides benefits of real-time, fast, label-free and sensitive applications, which is widely used in agricultural biotechnology, food safety, environmental monitoring, biological medicine, drug screening, and so on. However, the SPR optical bioanalyzer developed by international teams is so expensive that it is mainly a kind of specialized laboratory-based instrument used in harsh environmental conditions and can not be universally adopted so far in China. Furthermore, a cost-effective optical SPR bioanalyzers have not been investigated, therefore, it is of great theoretical and practical significances to develop a portable and cost-effective optical SPR bioanalyzer.Micro-channel system of biological samples is one of the core of an optical SPR bioanalyzers. The suitable sizes of micro-channel, precision machining and the sample flowing modes directly determines the whole performances of the bioanalyzer. Micro-channel system is composed of a SPR biosensor, a flow cell and a temperature control system. The optical SPR biosensor and flow cell are close enough to form a micro-channel, and a PID controller is used for controlling the temperature of the micro-channel to meet different needs for analyzing different biological samples in series, parallel and series-parallel connections, but the current micro-channel systems of the bio analyzer are designed for using in laboratory-based instruments. It is high costs and complex in structures due to using a thin film pressure valve, which can not be suitable for using in the portable optical SPR bioanalyzer. In order to develop a portable SPR biochemical analyzers, the current micro-channel system and a new micro-channel system studied for designing a portable optical bioanalyzers are very important, which will enable the portable optical SPR bioanalyzer to be widely used.Around the center for designing a cost-effective optical SPR bioanalyzer based on a micro-channel system, the flow rate, volume and temperature are systematic studied of the influences on analyzing biological samples in this thesis. An optical SPR signal processing algorithms suited for designing a portable SPR bioanalyzer has been proposed and then a numerical simulation was conducted using the engineering software MATLAB. The thesis gives detailed comparsion of the differences between the first order moment method and improved method for calculating the SPR positions while the optical resonance occurred on practical experiments. Two micro-channel systems for portable optical SPR bioanalyzer instrument have been constructed, which are connected in parallel and series-parallel modes. A temperature control system based on PID algorithm was designed, which includes the optical SPR biosensor, the flow cell, the micro-channel system and clamps and a dark environment is constructed for avoiding background light interruption.The SPR bioanalyzer based on the micro-channel systems has been developed using a multi-processors, a LCD touch-screen monitor and a peristaltic pump. The response curve is directly displayed on the touch-screen. Some experiments including ethanol, clenbuterol and hepatitis B were conducted using the portable SPR optical analysis. The results from the experiments showed that the short-term background noise of instruments is less than 5 RU. A high precision control of±0.01°C was obtained for the temperature controlling system and the concentration ranged from 10-10-10-3M was available to analyze.