In another experiment, the change in the absorbance was measured
after keeping the sol–gel coated glass slides in desiccators for
2 month (maximum time tested). The absorbance values of the
thin film at 598 nm were decreased only about 0.5% over a period
of 1 month. This result indicates that the sensor is very stable;
therefore, it can be stored for at least 2 months without losing its
characteristics.