Abstract
In this work, a novel nanocomposite consisting of electrosynthesized gold nanodendrites and chitosan nanoparticles (AuNDs/CSNPs) has been prepared to fabricate an impedimetric immunosensor based on a screen printed carbon electrode (SPCE) for the rapid and sensitive immunoassay of botulinum neurotoxin A (BoNT/A). BoNT/A polyclonal antibody was immobilized on the nanocomposite-modified SPCE for the signal amplification. The structure of the prepared nanocomposite was investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The charge transfer resistance (RCT) changes were used to detect BoNT/A as the specific immuno-interactions at the immunosensor surface that efficiently limited the electron transfer of Fe(CN)63−/4− as a redox probe at pH = 7.4. A linear relationship was observed between the %∆RCT and the concentration logarithm of BoNT/A within the range of 0.2 to 230 pg·mL−1 with a detection limit (S/N = 3) of 0.15 pg·mL−1. The practical applicability of the proposed sensor was examined by evaluating the detection of BoNT/A in milk and serum samples with satisfactory recoveries. Therefore, the prepared immunosensor holds great promise for the fast, simple and sensitive detection of BoNT/A in various real samples.
Highlights
Botulinum neurotoxin (BoNT), the most toxic substance known to man, remains one of the highest priority biological threat agents [1]
The results showed that the impedimetric signals of botulinum neurotoxin A (BoNT/A) are significantly improved in the presence of AuND/CSNPs as an excellent substrate of sensing layer
A label-free impedimetric immunosensor based on the AuNDs/CSNPs composite for the direct detection of BoNT/A was manufactured
Summary
Botulinum neurotoxin (BoNT), the most toxic substance known to man, remains one of the highest priority biological threat agents [1]. To address the mentioned problems, several methods have been reported for the determination of BoNT/A such as sandwich chemiluminescence enzyme immunoassay (ELISA) [5], capillary electrophoresis (CE) [2], surface plasmon resonance (SPR) [9], chemiluminescent [10], fluorescence [8], Endopep-mass spectrometry (MS) [11,12] and high performance liquid chromatography (HPLC) [13] These methods are generally slow, expensive and labor intensive. We propose a novel immunosensor for the impedimetric determination of BoNT/A based on immobilization of antibodies on the surface of a screen printed carbon electrode (SPCE) modified by AuNDs/CSNPs. The results showed that the impedimetric signals of BoNT/A are significantly improved in the presence of AuND/CSNPs as an excellent substrate of sensing layer. Conditions, the results showed that the proposed immunosensor could be successfully employed for the determination of BoNT/A in spiked milk and serum samples
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
