Abstract
The bio-sensing technology can be acted as an important role of molecular detection platform in disease detection and biomedical research, which not only provides details for bio-sample, but the information of sample concentration. In the experiment of sample detection, the concentration of the sample which should be tested will vary large differences; thus reaches the sensitivity of the apparatus, leading to the disable-detection of the presence of the sample. To manage the problem of low concentration, the common strategy is using inspissation technology, fitting the needs of the detection. However, the above technology, for example, high-speed centrifugation, for small samples, should take longer times and higher the risk of metamorphism. Thus, high efficiency of the inspissation technology should be necessarily researched. Due to the system of nanochannel, it helps make many kinds of bio-chips; thus helping us to do the complete experiment for bio-sample. Therefore, our research is aimed at making components for bio-chips, making high efficiency progress at bio-detection for concentrating molecules. For the design of this experiment, we additionally fabricate nanochannel with electric field through electric double layer effect to accomplish the effective inspissation of molecules. And for the fabrication part, we first use Focused Ion Beam, FIB, to make nanowires at the mold of SU-8; then we use soft-lithography with Polydimethylsiloxane, PDMS, to finish our microchannles. Based on the references, they indicated that the geometry of the microchannel will affect the molecular-collection of the efficiency. So, our research also aim at changing the width of the microchannel. For our geometry, we design the width of 30μm, 20μm and 10μm respectively, investigating the changing of the width and see what’s affecting our collection-efficiency. The whole research can be distinguished into two parts, simulation and experiment. The simulation is to use the approach of Finite Element Method, FEM, to change the potential, discussing different kinds of nanochannel-width, microfluidic electric field and electro-osmotic flow. And for the experiment part, we observe the results of the collection of fluorescent molecules in different microchannel-width first. The experiment result indicates that 20μm width of microchannel has the highest collection-efficiency. Besides, when changing dimensions smaller, the collection-efficiency will enhance. The second part we discuss while happening blockage of the nanochannel when used, what will be affected for the electric double layer. The second part shows that while severely blocked the nanochannel, the effect of the electric double layer will be more obvious and finely-collect.