An optical oxygen sensor and reaction vessel for high-pressure applications

We describe a simple hyperbaric chamber and optical oxygen probe (optrode), which is based on the dynamic fluorescent quenching of a ruthenium metal c omplex, that can be used to measure changes in oxygen concentration in eith er aqueous or gaseous media. Initial experiments illustrate the utility of this robust form of sensor. The optrode showed a typical response time of < 10 s, a linear temperature response with greater fluorescent quenching at l ower temperatures, and was unaffected by pressures as great as 34.4 mPa (34 0 atm). Yeast cultures measured at 27.8 mPa (275 atm) showed an up to ninef old decrease in respiration rate compared to cells at 1 atm. The oxygen opt rode is a simple and rugged device that appears exceptionally well suited f or experimentation under conditions in which polarographic electrodes or co nventional chemical analysis is difficult, e.g., at high or variable pressu res.