TY - JOUR
T1 - Sensitive and selective methanol biosensor using two-enzyme cascade reaction and fluorometry for non-invasive assessment of intestinal bacteria activity
AU - Toma, Koji
AU - Iwasaki, Kanako
AU - Arakawa, Takahiro
AU - Iwasaki, Yasuhiko
AU - Mitsubayashi, Kohji
N1 - Funding Information:
This work was partly supported by Japan Society for the Promotion of Science (JSPS, Japan) KAKENHI Grant Number JP 17H01759 , 16KK0143 and 15H04013 ; a grant from Japan IDDM network; the Ministry of Education, Culture, Sports, Science and Technology (MEXT, Japan) Special Funds for “Cooperative Research Project of Research Center for Biomedical Engineering”.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/6/1
Y1 - 2021/6/1
N2 - For understanding the status of intestinal flora non-invasively, methanol (MeOH) has been attracting the attention. In this study, we have developed and compared two different liquid-phase methanol biosensors. One, referred to as the AOD electrosensor, utilized alcohol oxidase (AOD) and an oxygen electrode. It electrochemically measured the decrease in oxygen through AOD-catalyzed oxidation of MeOH. The other, referred to as the AOD-FALDH fluorosensor, exploited a cascade reaction of AOD and formaldehyde dehydrogenase (FALDH) in conjunction with a fiber-optic sensor. It measured increase in the fluorescence from reduced form of β-nicotinamide adenine dinucleotide (NADH) that was a final product of the two-enzyme cascade reaction. Due to the cascade reaction, the AOD-FALDH fluorosensor showed 3 times better sensitivity along with 335 times wider dynamic range (494 nM–100 mM) than those of the AOD electrosensor (1.5–300 μM). The selectivity to MeOH was also improved by the cascade reaction with AOD-FALDH as no sensor output was observed from other aliphatic alcohols than MeOH in contrast to the AOD electrosensor. Although the use of FALDH resulted in the increase in the sensor output from aldehydes, such as acetaldehyde and formaldehyde, considering their concentrations in body fluids, the influence on the sensor output is limited. These results indicate that incorporating the cascade reaction into fluorometry enables enhanced biosensing of MeOH that will be useful for assessment of intestinal flora with little burden.
AB - For understanding the status of intestinal flora non-invasively, methanol (MeOH) has been attracting the attention. In this study, we have developed and compared two different liquid-phase methanol biosensors. One, referred to as the AOD electrosensor, utilized alcohol oxidase (AOD) and an oxygen electrode. It electrochemically measured the decrease in oxygen through AOD-catalyzed oxidation of MeOH. The other, referred to as the AOD-FALDH fluorosensor, exploited a cascade reaction of AOD and formaldehyde dehydrogenase (FALDH) in conjunction with a fiber-optic sensor. It measured increase in the fluorescence from reduced form of β-nicotinamide adenine dinucleotide (NADH) that was a final product of the two-enzyme cascade reaction. Due to the cascade reaction, the AOD-FALDH fluorosensor showed 3 times better sensitivity along with 335 times wider dynamic range (494 nM–100 mM) than those of the AOD electrosensor (1.5–300 μM). The selectivity to MeOH was also improved by the cascade reaction with AOD-FALDH as no sensor output was observed from other aliphatic alcohols than MeOH in contrast to the AOD electrosensor. Although the use of FALDH resulted in the increase in the sensor output from aldehydes, such as acetaldehyde and formaldehyde, considering their concentrations in body fluids, the influence on the sensor output is limited. These results indicate that incorporating the cascade reaction into fluorometry enables enhanced biosensing of MeOH that will be useful for assessment of intestinal flora with little burden.
KW - Enzymatic cascade reaction
KW - Fluorescence
KW - Intestinal flora
KW - Liquid-phase biosensor
KW - Methanol
KW - Oxygen electrode
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U2 - 10.1016/j.bios.2021.113136
DO - 10.1016/j.bios.2021.113136
M3 - Article
C2 - 33714857
AN - SCOPUS:85102261663
VL - 181
JO - Biosensors and Bioelectronics
JF - Biosensors and Bioelectronics
SN - 0956-5663
M1 - 113136
ER -