Dispersing gold nanoparticles on thiolated polyaniline-multiwalled carbon nanotubes for development of an indole-3-acetic acid amperometric immunosensor. Issue 9 (5th August 2019)

• Record Type: Journal Article
• Authors: Su, Zhaohong; Cheng, Yongbing; Li, Chaorong; Xiong, Yuanfu; Xiao, Langtao; Chen, Shu; Qin, Xiaoli
• Is Part Of: Nanoscale advances. Volume 1:Issue 9(2019)
• Page Start: 3607
• Page End: 3613
• Publication Date: 2019-08-05
• Subjects: 620.5
• DOI: 10.1039/c9na00258h
• Languages: English
• ISSNs: 2516-0230

Abstract

Abstract : An amperometric immunosensor based on new thiolated bionanocomposite with a high dispersion of gold nanoparticles (AuNPs) for the sensitive detection of indole-3-acetic acid (IAA) is being reported herein. Abstract : An amperometric immunosensor based on new thiolated bionanocomposite with a high dispersion of gold nanoparticles (AuNPs) for the sensitive detection of indole-3-acetic acid (IAA) is being reported herein. Briefly, a thiolated nanocomposite was prepared via the microwave-assisted thiol–ene reaction of 2, 5-dimercapto-1, 3, 4-thiadiazole (DMcT) with oxidized polyaniline (PANI), which was synthesized in the presence of multiwalled carbon nanotubes (MWCNTs), yielding thiolated polyaniline (TPANI)-MWCNTs. Further, AuNPs were deposited on the TPANI-MWCNTs by microwave-assisted method to obtain a AuNPs/TPANI-MWCNTs nanocomposite. Finally, the thiolated bionanocomposite film was constructed via the specific chemical reaction between boronic acid functionalized AuNPs and the vicinal diol functionalized AuNP labeled immunoglobulin G (IgG–AuNPs). The change in the reduction peak current of Fe(CN)6 3− was used to monitor the immunoreaction between IAA and antibody. The TPANI-MWCNT nanocomposites uniformly disperse AuNPs, IgG–AuNPs and anti-IAA-AuNPs, leading to the amplification of the signal of the immunosensor. Fourier transform infrared spectra (FTIR), cyclic voltammetry (CV), transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV-vis) and differential pulse voltammetry (DPV) were used to characterize the nanocomposite film and the stepwise modification of the immunosensor. The prepared thiolated bionanocomposite material has good biocompatibility, a highly uniform dispersion of the AuNPs with a narrow size distribution as verified by TEM, and high load/activity of the immobilized antibody proved via DPV. The fabricated IAA amperometric immunosensor not only exhibits a good linear arrange from 1.0 pg mL −1 to 10 ng mL −1 with the limit of detection of 0.97 pg mL −1 (S/N = 3), but also possesses good selectivity, reproducibility and stability for the detection of IAA.