Affiliation: | a Department of Public Health and Clinical Medicine, Occupational Medicine, Umeå University, S-905 81 Umeå, Sweden b Cranfield Biotechnology Centre, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK c Department of Chemistry, National Institute for Working Life, P.O. Box 7654, S-907 13 Umeå, Sweden |
Abstract: | The possibility of developing a simple, inexpensive and specific personal passive “real-time” air sampler incorporating a biosensor for formic acid was investigated. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase (FDH) with nicotinamide adenine dinucleotide (NAD+) as a co-factor and Meldola's blue as mediator. An effective way to immobilise the enzyme, co-factor and Meldola's blue on screen-printed, disposable, electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. Steady-state current was reached after 4–15 min and the limit of detection was calculated to be below 1 mg/m3. However, the response decreased by 50% after storage at −15°C for 1 day. |