Chang Q, Randers-Eichhorn L, Lakowicz J R, Rao G
Medical Biotechnology Center, University of Maryland Biotechnology Institute, Second Floor, 725 West Lombard Street, Baltimore, Maryland 21201, USA.
Biotechnol Prog. 1998 Mar-Apr;14(2):326-31. doi: 10.1021/bp970119k.
An autoclavable sensing film was developed for monitoring dissolved CO2. The sensing film, based on fluorescence resonance energy transfer (FRET), consisted of a fluorescent donor, an acceptor, and a quaternary ammonium hydroxide, which were doped in a two-component silicone film. As no aqueous solution was used in the sensing film matrix, the sensing film was unaffected by osmotic pressure. Fluorescence lifetime was selected as the sensing parameter, and measured in frequency domain using phase fluorometry. Upon exposure to 20% CO2-saturated water, a 43 degrees increase in phase angle was observed at 100 MHz. The process was fully reversible when the sensing film was exposed to nitrogen-saturated water. The estimated response and recovery times for 90% signal change were 1 min (for a step change from 0 to 6.7% CO2-saturated water) and 1.5 min (for a step change from 6.7 to 3.3% CO2-saturated water). When used for on-line monitoring of dissolved CO2 produced by a culture of Escherichia coli, the sensing film showed a similar trend to that obtained from off-line measurements using a wet chemistry analyzer.
开发了一种可高压灭菌的传感膜用于监测溶解的二氧化碳。该传感膜基于荧光共振能量转移（FRET），由荧光供体、受体和氢氧化季铵组成，它们被掺杂在双组分硅氧烷膜中。由于传感膜基质中未使用水溶液，因此传感膜不受渗透压影响。选择荧光寿命作为传感参数，并使用相荧光法在频域中进行测量。当暴露于20%二氧化碳饱和水时，在100 MHz下观察到相角增加了43度。当传感膜暴露于氮气饱和水时，该过程是完全可逆的。估计90%信号变化的响应时间和恢复时间分别为1分钟（从0到6.7%二氧化碳饱和水的阶跃变化）和1.5分钟（从6.7到3.3%二氧化碳饱和水的阶跃变化）。当用于在线监测大肠杆菌培养产生的溶解二氧化碳时，传感膜显示出与使用湿化学分析仪进行离线测量相似的趋势。
