Bioelectrocatalytic Detection of Histamine Using Quinohemoprotein Amine Dehydrogenase and the Native Electron Acceptor Cytochrome c-550

Bioelectrocatalytic sensor of histamine has been constructed using quinohemoprotein amine dehydrogenase (QH-AmDH) as an enzyme and its native electron acceptor cytochrome c-550 (Cyt c-550) as a mediator. Highly reversible electron transfer of Cyt c-550 is achieved at bis(4-pyridyl)disulfide-modified Au electrodes. The electron transfer from substrate-reduced QH-AmDH to oxidized Cyt c-550 is in the diffusion-controlled region, in spite of relatively small redox potential difference. QH-AmDH and Cyt c-550 can be co-entrapped on the electrode surface with a suitable dialysis membrane. As a result, Cyt c-550 is found to be an excellent mediator compared with other artificial ones. The sensor allows the histamine detection down to 500 nM (S/N=3) and the linearity is retained up to 1.5 mM with a relative standard deviation of 4.8 % at 10 µM histamine (n=6). The performance of the histamine biosensor is discussed in view of clinical chemistry.