Table 1 Comparison of operational characteristics of biosensors created using different types of urease immobilization
Type of immobilization | Noise (μA) | Drift of base line (μA/min) | Detection limit (mM) | RSd of reproducibility of signal (%) | RSd of inter-reproducibility of immobilization (%) | Linear range (mM) |
---|---|---|---|---|---|---|
In GA vapour | 0.02 | 0.010 | 0.0015 | 8.5 | 27.4 | 0 to 0.5 |
On the surface of silicalite monolayer | 0.03 | 0.028 | 0.0015 | 4.7 | 10.5 | 0 to 1.5 |
On the surface of nano beta zeolite monolayer | 0.03 | 0.001 | 0.0015 | 3.4 | 17.8 | 0 to 1.0 |
On the surface of zeolite L monolayer | 0.06 | 0.004 | 0.0050 | 4.5 | 15.4 | 0 to 1.5 |
On the surface of calcinated nano beta zeolite monolayer | 0.09 | 0.013 | 0.0055 | 4.7 | 14.3 | 0 to 1.0 |