Study On Preparation Of Super-paramagnetic Beads And Its Application On Microfluidic Chip System

As one of the most important biological analytic methods, immunoassay is widely used in clinical diagnosis and biological researches. But the shortcoming of general immunoassay restricts its application in point of care test (POCT).Microfluidic chip, a novel miniaturized analytic platform, uses micromechanical technology to construct a liquid circuit system composed of various mini functional components. It can process one or a series of analyses on a chip and high speed and throughput assay can be achieved. It shows great advantages in immunoassay. Portable and easy to be integrated, it can be conveniently used in POCT. It decreases reagent consume to reduce assay costs. Detection, separation or other complicated operations can be completed within seconds on microfluidic chip due to its high analysis efficiency,However, nowadays, most microfluidic chip can be used only once, which has caused high analytic costs. And, there is great system error existing between different chips due to the restriction of machining technique. Furthermore, in most microfluidic chips, antibodies are linked directly in the microchannels, which may cause denaturalization of antibodies, non-special adsorption and reduction of analytic sensitivity.In our research, we use super-paramagnetic microbeads as solid carrier of antibody or antigen based on its character and we construct an electromagnetic fields to realize the enrichment of magnetic beads and the location of immune reaction. Therefore, the microfluidic chip can be reused. We combine microfluidic chip, super-paramagnetic microbeads and chemiluminescent technology with the aim to find a kind of immunoassay system based on microfluidic chip which will meet the needs of immunoassay in various special environments, such as in primary hospital and military affairs. The main results and conclusions are summarized as follows:1.The Fe₃O₄ magnetic fluid is prepared by chemical codeposition. The width distribution and magnetic response are detected and optimized. The width of magnetic fluid is under 1.2-1.5μm. And then, the magnetic fluid, acted as magnetic core, is packaged with...