A Low-Cost Fluorescent Sensor for pCO2 Measurements

Abstract

Global warming is believed to be caused by increasing amounts of greenhouse gases (mostly CO 2) discharged into the environment by human activity. In addition to an increase in environmental temperature, an increased CO 2 level has also led to ocean acidification. Ocean acidification and rising temperatures have disrupted the water's ecological balance, killing off some plant and animal species, while encouraging the overgrowth of others. To minimize the effect of global warming on local ecosystem, there is a strong need to implement ocean observing systems to monitor the effects of anthropogenic CO 2 and the impacts thereof on ocean biological productivity. Here, we describe the development of a low-cost fluorescent sensor for pCO 2 measurements. The detector was exclusively assembled with low-cost optics and electronics, so that it would be affordable enough to be deployed in great numbers. The system has several novel features, such as an ideal 90° separation between excitation and emission, a beam combiner, a reference photodetector, etc. Initial tests showed that the system was stable and could achieve a high resolution despite the low cost.

Characterization of a Time-Domain Dual Lifetime Referencing pCO2 Optode and Deployment as a High-Resolution Underway Sensor across the High Latitude North Atlantic Ocean

“…This laboratory precision is significantly better than the desired 2 µatm precision (Pierrot et al, 2009), and is similar to 1 µatm achieved by Lefevre et al (1993) with a spectrophotometric sensor, and 1.7 µatm reported by Ge et al (2014).…”

Dynamics of benthic metabolism, O2, and pCO2 in a temperate seagrass meadow

“…The probe was calibrated by the manufacturer prior to the study, and the internal zeroing baseline correction ensured minimum drift. More information on the sensor is given by Schar et al (), Wanninkhof et al (), and Ge et al ().…”

Carbon Dioxide Sensing—Biomedical Applications to Human Subjects

“…The most basic sensors use a single wavelength for illumination—in case of absorbance measurements—or a pair of excitation-emission wavelengths—in case of luminescence measurement. Photobleaching may be compensated for, using more wavelengths and ratiometric methods similar to that driving pulse oximetry [ 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 ], while variations in the emitted light intensities or sensitivities toward received light can be addressed by using referencing—i.e., taking a measurement in pure di-nitrogen (N ) and/or pure CO prior to CO measurement for sensor calibration purposes [ 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 ].…”