A nitrite biosensor based on a maltose binding protein nitrite reductase fusion immobilized on an electropolymerized film of a pyrrole-derived bipyridinium.
The preparation and electrochemical characterization of glassy carbon electrodes (GCEs) modified with electropolymerized films of the cation N-(3-pyrrol-1-yl-propyl)-4,4'-bipyridine (PPB) are described. The behavior of a new biosensor, which exhibits a high catalytic activity for nitrite reduction and which consists of a maltose binding protein nitrite reductase fusion (MBP-Nir) immobilized on an electropolymerized film of PPB as an electrocatalyst, is also described. The insoluble perchlorate salt of the poly(benzyl viologen) dication was used to immobilize MBP-Nir onto an electrode previously modified with an electropolymerized film of PPB. The electropolymerized film of PPB on the GCE is redox active and exhibits special electron-transfer properties toward the MBP-Nir layer but not toward Nir (Nir without MBP fusion attached), suggesting an intimate interaction between the PPB film and the MBP-Nir layer. The kinetics of the catalytic reaction between the biosensor and nitrite anion were characterized using cyclic voltammetry and rotated disk electrode techniques, and a value of (4.6 +/- 0.5) x 10(3) M-1 S-1 was obtained for the rate constant.
Wu
Q
Q
Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
Storrier
G D
GD
Pariente
F
F
Wang
Y
Y
Shapleigh
J P
JP
Abruña
H D
HD
D015374:Biosensing Techniques; D002352:Carrier Proteins / Q000737:chemistry*; D004800:Enzymes, Immobilized; D007202:Indicators and Reagents; D058619:Maltose-Binding Proteins; D008567:Membranes, Artificial; D009572:Nitrite Reductases / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry*; D011108:Polymers; D011726:Pyridinium Compounds / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry
D002352:Carrier Proteins; D004800:Enzymes, Immobilized; D007202:Indicators and Reagents; D058619:Maltose-Binding Proteins; D008567:Membranes, Artificial; D009573:Nitrites; D011108:Polymers; D011726:Pyridinium Compounds; D011758:Pyrroles; D009572:Nitrite Reductases