For enzyme immobilization, it is necessary to ensure the inhibition of methods or materials against enzyme activity as less as possible. Effects of aptamer on the enzyme activity were investigated and it showed that Apt5 and Apt9 had no obvious inhibition on enzyme activity while Apt3 could significantly enhance activity by nearly 3 folds (data not shown). From the influence of pH and ion strength, it is known that the interaction between aptamer and PGUS-E was stable enough to tolerate the whole catalytic process. It was interesting that the PGUS-E immobilized by aptamer had a higher specific activity than the free form under 40 °C reaction (Fig. 6A). This may be attributed to the local substrate enrichment effect of the magnetic beads since they can absorb the GL to its surface. On the other hand, the immobilization via aptamer was so flexible and gentle that it had no inhibition to enzyme activity. In addition, the PGUS-E connected with Apt9 was immobilized under 40 °C, so it lost some activity due to the heat shock effect and showed two times lower specific activity compared to Apt5 in a single batch reaction.