Impedimetric immunosensor for the label-free and direct detection of botulinum neurotoxin serotype A using Au nanoparticles/graphene-chitosan composite.
In this work, a novel nanocomposite film consisting of the Au nanoparticles/graphene-chitosan has been designed to construct an impedimetric immunosensor for a rapid and sensitive immunoassay of botulinum neurotoxin A (BoNT/A). BoNT/A antibody was immobilized on glassy carbon electrode modified with Au nanoparticles/graphene-chitosan for the signal amplification. The fabrication of immunosensor was extensively characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The impedance changes, due to the specific immuno-interactions at the immunosensor surface that efficiently restricted the electron transfer of redox probe Fe(CN)64-/3-were utilized to detect BoNT/A. The measurements were highly targeted specific and linear with logarithmic BoNT/A concentrations in PBS, milk and human serum across a 0.27-268pgmL-1range and associated with a detection limit of 0.11pgmL-1.
Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran. Electronic address: afkhami@basu.ac.ir.
Abbas
A
Afkhami
Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.
Pegah
P
Hashemi
Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Hasan
H
Bagheri
Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Jafar
J
Salimian
Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Ali
A
Ahmadi
Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.
Tayyebeh
T
Madrakian
D015374:Biosensing Techniques; D019274:Botulinum Toxins, Type A / Q000737:chemistry / Q000302:isolation & purification*; D002244:Carbon / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry; D058266:Dielectric Spectroscopy; D006046:Gold; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared
D002244:Carbon; D006046:Gold; D048271:Chitosan; D019274:Botulinum Toxins, Type A
Botulinum neurotoxin A; Electrochemical impedance spectroscopy; Immunosensor; Impedimetric immunosensor; Lable free biosensors