Preparation and properties of immobilized mercuric reductase in porous glass carriers

The immobilized mercuric reductase covalently coupled to porous glass was prepared and its properties were investigated. Mercuric reductase immobilized on arylamino and carboxyl derivatives exhibited high relative activities about 20-30% compared with soluble enzymes. The optimum pH of mercuric reductase immobilized on these derivatives was 7.5, slightly higher than that of soluble state (7.0-7.2). The stability of mercuric reductase increased with immobilization onto arylamino derivative and the immobilized enzyme maintained at 30°C for 29 days showed 80-90% of initial activity. As the application of immobilized enzyme, mercuric ion sensor was prepared and it was found that mercuric ion higher than 0.5 μM was detectable with this sensor.