title: Escherichia coli and its application in a mediated amperometric glucose sensor.
abstract: Escherichia coli cells, which contain apo-glucose dehydrogenase, were used in constructing a mediated amperometric glucose sensor. The E. coli modified glucose sensor, which was prepared by immobilizing E. coli cells behind a dialysis membrane on a carbon paste electrode containing 2,3-dimethoxy-5-methyl-1,4-benzoquinone (Q(0)), produced a current for the electrocatalytic oxidation of glucose with Q(0) as an electron transfer mediator only after the addition of a trace amount of pyrroloquinoline quinone (PQQ), the cofactor of the enzyme. This allows a novel method of glucose measurements free from the interference of the redox active substances, if contained, in a sample solution. The glucose sensor was insensitive to dioxygen; the currents measured under anaerobic and aerobic conditions, and even under dioxygen saturated conditions were almost the same in magnitude at a given concentration of glucose over the range of 0.2-10 mM. Response time of the glucose sensor was 2 min to attain 90% level of the steady-state current. The E. coli modified glucose sensor was reusable when treated with ethylenediaminetetraacetic acid (EDTA). When E. coli cells were lyophilized, they could be stored at room temperature in a dry box for more than six months without loss of the catalytic activity.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606 8502, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Ito
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Yamazaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Kano
authors.forename: Tokuji
authors.initials: T
authors.lastname: Ikeda
mesh_terms: D018441:Biofilms; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002478:Cells, Cultured; D003470:Culture Media / Q000378:metabolism; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D004926:Escherichia coli / Q000378:metabolism*; D005947:Glucose / Q000032:analysis* / Q000378:metabolism; D005948:Glucose Dehydrogenases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D010084:Oxidation-Reduction; D045542:PQQ Cofactor; D011786:Quality Control; D015363:Quinolones / Q000378:metabolism; D011809:Quinones / Q000378:metabolism; D012680:Sensitivity and Specificity; D013696:Temperature
chemical_list: D003470:Culture Media; D008567:Membranes, Artificial; D015363:Quinolones; D011809:Quinones; D045542:PQQ Cofactor; D005948:Glucose Dehydrogenases; C033955:glucose dehydrogenase (pyrroloquinoline-quinone); D005947:Glucose