Biotinylated polypyrrole films: an easy electrochemical approach for the reagentless immobilization of bacteria on electrode surfaces.
Biotinylated bacteria were immobilized onto biotin/avidin modified electrode surfaces. Firstly, an electrospotting deposition method, followed by fluorescence microscopy, showed that bacteria were specifically grafted onto a gold surface. Fluorescence intensity versus the quantity of bacteria deposited on the surface was correlated, allowing determination of the microbial saturation point. Secondly, biotinylated bacteria were immobilized onto a glassy carbon macro-electrode in order to assess immobilized bacterial denitrification activity. During a 7-day trial, the modified electrode completely denitrified 5 mM nitrate, with a rate of 1.66 mM/day over the first 3 days. When the same electrode was placed in fresh nitrate solution, the denitrification rate dropped to 0.80 mM/day. Crucially, the immobilized bacteria did not become detached from the electrode during the study.
Da Silva
S
S
Laboratoire d'Electrochimie Organique et de Photochimie Redox, URA UMR CNRS 5630, Université Joseph Fourier Grenoble 1, BP53 38041 Grenoble, Cedex 9, France.
Grosjean
L
L
Ternan
N
N
Mailley
P
P
Livache
T
T
Cosnier
S
S
D001422:Bacterial Adhesion / Q000502:physiology*; D001681:Biological Assay / Q000379:methods; D015374:Biosensing Techniques / Q000379:methods*; D019921:Biotinylation / Q000379:methods; D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival / Q000502:physiology; D018914:Cells, Immobilized / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D007202:Indicators and Reagents; D009566:Nitrates / Q000378:metabolism; D042084:Paracoccus pantotrophus / Q000166:cytology* / Q000378:metabolism; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*
D020099:Coated Materials, Biocompatible; D007202:Indicators and Reagents; D009566:Nitrates; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole