CASTDan:Abstract15
Kostov, Y., Ge, X., Rao, G. (2002) High-stability non-invasive autoclavable naked optical CO2 sensor. Biosensors and Bioelectronics. 18 857-865.
Abstract:
The fabrication and characterization of a high-stability non-invasive autoclavable naked optical CO2 sensor is described in this
report. The sensor was made by using 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) as the fluorescence dye and
cetyltrimethylammonium hydroxide (CTMAOH) as the phase transfer agent (the base). A highly hydrophobic two-component
silicone film was used as the polymer matrix, which overcame some of the limitations of the existing plastic type CO2 sensors, such as
dye leaching and cross-sensitivity to ions. To improve the stability of the sensor, several affecting factors were investigated.
Experimental results showed that sufficient base and a small amount of water in the sensing film were critical factors that affected
the stability of the sensor. Although the sensor was more stable when kept in water, the function of the sensor could recover when
the sensor kept in air was transferred into water. The sensor has a lifetime of several months. The detection limit of the sensing film
was about 0.03%. The average response and recovery times were 0.66 and 1.94 min, respectively. It had no cross-sensitivity to salt
concentrations in the range of 0~0.2 M and to pH in the range of 5.6~8.0, so it can be used in processes with changing ion
concentration and pH. It was sterilizable and could be autoclaved many times without losing its sensitivity. The applicability of the
sensor in real application was successfully tested in the fermentation of Escherichia coli .
2002 Elsevier Science B.V. All rights reserved.
