Detection of Immunoglobulin Molecules Using a Electrothermal-Effect Enhanced Quartz Crystal Microbalance

In order to get rid of the limitation of slow transportation of pure diffusion, electrothermal effect (ETE) is introduced in this work to enhance the performance of the QCM sensor. An advanced quartz crystal microbalance (QCM) is built with a reaction chamber modified by assemblying our designed with multi-microelectrodes to produce electrothermal vortices flow which increase the opportunity of the specific binding of the immobilized ligand and the target molecules carried in the fluid flow. By applying 10 Vpp and 10 MHz to the microelectrode pairs to generate electrothermal flow in this experimental study, this thesis compares the cases with ETE applied and without ETE to show that the human IgG1 can be more efficiently detected in this system with ETE effect. In this work, a specific binding of Human IgG1 in the fluid flow and the immobilized Anti-Human IgG1 is processed. The chip will first be modified to make it be capable of binding the certain ligands. After coating Anti-Human IgG1 to the reaction surface, wait until it is stable and measure the resonant frequency. Inject the Human IgG1 fluid and apply ETE to raise the specific binding and increase the mass load. Finally, measure the steady-state resonant frequency in gas phase and calculate the frequency shift. In the cases of different concentrations, there are big improvements noticed by observing the changes of shift of resonant frequency. Besides, it can also get further proved through Fluorescent dye marker. Consequently, ETE is functional to increase the mass-binding and improved the detection of efficiency.