Peer-Reviewed Journal Details
Mandatory Fields
Borchert, NB,Kerry, JP,Papkovsky, DB
2013
January
Sensors and Actuators B-Chemical
A CO2 sensor based on Pt-porphyrin dye and FRET scheme for food packaging applications
Validated
WOS: 40 ()
Optional Fields
Optical CO2 sensor FRET system Ion-pairing Porphyrin Food packaging Migration studies DISSOLVED CARBON-DIOXIDE ALPHA-NAPHTHOLPHTHALEIN FLUORESCENT PORPHYRIN COLORIMETRIC CHANGE OPTICAL SENSOR GAS SENSOR OXYGEN PH COMBINATION SYSTEM
176
157
165
An optochemical CO2 sensor is described which uses a phosphorescent reporter dye PtTFPP and a colourimetric pH indicator alpha-naphtholphthalein incorporated in plastic matrix together with a phase transfer agent tetraoctyl- or cetyltrimethylammonium hydroxide. Good spectral overlap of PtTFPP emission and alpha-naphtholphthalein absorption at around 650 nm provides efficient energy transfer from PtTFPP via FRET mechanism, thus reducing its phosphorescence lifetime. Experiments were carried out to optimize the composition and working characteristics of such a sensor for the measurement of headspace CO2 in foods packaged under modified atmosphere. The resulting thin film sensor coatings showed robust optical responses to CO2, response (1 min, 99.9%) and recovery times (4 min, 99.9%) from 0 to 100% CO2. As expected, the CO2 sensor showed significant cross-sensitivity to O-2 quenching, and this was accounted for by a tandem O-2 sensor having similar phosphorescent characteristics but no CO2 sensitivity. Upon storage in an open container, the sensors were stable for at least 14 days at 4 degrees C and 50 days at -20 degrees C, however at room temperature they were seen to deteriorate within 7 days loosing colour and sensitivity to CO2. At the same time, in food and modified atmosphere environment the sensor retained its sensitivity to CO2 for 21 days at 4 degrees C which is sufficient for many packaged products. Migration of sensor components examined with a standard set of standard food stimulants was only detectable in 95% ethanol and in olive oil for PtTFPP (0.06-0.13 mu g/ml) and in 50% and 95% ethanol for alpha-naphtholphthalein (9.86-21.65 mu g/ml). (C) 2012 Elsevier B.V. All rights reserved.
10.1016/j.snb.2012.09.043
Grant Details