Impedimetric immunosensor based on a polypyrrole-antibiotic model film for the label-free picomolar detection of ciprofloxacin.
This paper describes the construction of an impedimetric immunosensor for the label-free detection of ciprofloxacin, an antibiotic belonging to synthetic fluoroquinolones. A poly(pyrrole-N-hydroxysuccinimide) film was electrogenerated onto electrodes and then used for the reagentless covalent binding of a fluoroquinolone model bearing an amino group. The resulting electrodes were utilized to immobilize a layer of anticiprofloxacin antibody onto the polymer surface by immunoreaction. In presence of ciprofloxacin, the antibody was displaced in solution inducing marked changes in the impedance of the sensor electrodes. These phenomena were detected and characterized by electrochemical impedance spectroscopy allowing the selective detection of extremely low ciprofloxacin concentration, namely, 1 x 10(-12) g mL(-1) or 3 pmol L(-1). Sensors exposed to ciprofloxacin showed a decrease in the sum of the interfacial resistances with the increase in ciprofloxacin concentration from 1 x 10(-12) to 1 x 10(-6) g mL(-1).
Giroud
Fabien
F
Département de Chimie Moléculaire UMR-5250, ICMG FR-2607, CNRS, Université Joseph Fourier, BP-53, 38041 Grenoble Cedex 9, France.
Gorgy
Karine
K
Gondran
Chantal
C
Cosnier
Serge
S
Pinacho
Daniel G
DG
Marco
M-Pilar
MP
Sánchez-Baeza
Francisco J
FJ
D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000276:immunology; D055910:Antibodies, Immobilized / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D002939:Ciprofloxacin / Q000032:analysis* / Q000276:immunology; D017097:Electric Impedance; D004563:Electrochemistry; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D055910:Antibodies, Immobilized; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D002939:Ciprofloxacin