Fluorometric gas-phase biosensor (bio-sniffer) with UV-LED emission light for formaldehyde vapor

A fibre-optic biochemical gas sensor (bio-sniffer) for gaseous formaldehyde (FA) was developed and applied for on-site assessment of FA detoxification. The bio-sniffer measures FA as a fluorescence of reduced nicotinamide adenine dinucleotide (NADH) which is the product of formaldehyde dehydrogenase reaction. The detection limit of the bio-sniffer for gaseous FA was 2.5 ppb, which is enough lower for the purpose of evaluating FA detoxification. The bio-sniffer was then applied to measure phytoremediation with N. E. “Bostoniensis”. The FA level in the measurement chamber decreased down to the detection limit (2.5 ppb), which is lower level than FA level of room air (12 ppb), within 95 min and the value increased to FA level when the chamber was vented.