In the past few years, gene therapy, genetic modification and other related issues are the focuses in development of biotechnology. A good biosensor is also important to be used in some relevant biomedical research. In this study, we used the surface plasmon resonance (SPR) biosensors, a kind of biosensors, to perform experiments. Firstly, we studied how to prepare an optimal modification surface by using thiolated DNA and MCH. Then, we investigated the effect of using DNA probes with different spacer lengths on the DNA hybridization reactions. We use some DNA probes have 10, 20 or 26 continuous thymine bases at 5’ end. The hybridization efficiency of DNA on different surfaces of DNA chips was evaluated by a surface plasomon resonance (SPR) imaging. The experimental results indicate that the DNA probe with 10-thymine bases spacer shows the best hybridization efficiency. Besides, we used our home-made SPR instrument to study the interactions between the thrombin and two aptamers. One of these two aptamers had 10 continuous thymine bases at 5’ end; another one didn’t have any spacer at 5’ end. The result indicates that the aptamer had a spacer immobilized on sensor surface can interact with the thrombin better.
