Designing Electrochemical Interfaces with Functionalized Magnetic Nanoparticles and Wrapped Carbon Nanotubes as Platforms for the Construction of High-Performance Bienzyme Biosensors

Abstract

The design of a novel biosensing electrode surface, combining the advantages of magnetic ferrite nanoparticles (MNPs) functionalized with glutaraldehyde (GA) and poly(diallyldimethylammonium chloride) (PDDA)-coated multiwalled carbon nanotubes (MWCNTs) as platforms for the construction of high-performance multienzyme biosensors, is reported in this work. Before the immobilization of enzymes, GA-MNP/PDDA/MWCNT composites were prepared by wrapping of carboxylated MWCNTs with positively charged PDDA and interaction with GA-functionalized MNPs. The nanoconjugates were characterized by scanning electron microscopy (SEM) and electrochemistry. The electrode platform was used to construct a bienzyme biosensor for the determination of cholesterol, which implied coimmobilization of cholesterol oxidase (ChOx) and peroxidase (HRP) and the use of hydroquinone as redox mediator. Optimization of all variables involved in the preparation and analytical performance of the bienzyme electrode was accomplished. At an applied potential of -0.05 V, a linear calibration graph for cholesterol was obtained in the 0.01-0.95 mM concentration range. The detection limit (0.85 μM), the apparent Michaelis-Menten constant (1.57 mM), the stability of the biosensor, and the calculated activation energy can be advantageously compared with the analytical characteristics of other CNT-based cholesterol biosensors reported in the literature. Analysis of human serum spiked with cholesterol at different concentration levels yielded recoveries between 100% and 103%

Preparation of Biocompatible Palladium-Fe3O4 Nanoparticles/Multiwalled Carbon Nanotubes Composite and its Electrocatalytic Activity towards Determination of Cholesterol on Screen Printed Electrode

“…PDDA is a water soluble, quaternary ammonium cationic polyelectrolyte. It is positively charged colloid when dissolved in aqueous solutions [31,32]. The positively charged PDDA polymer can be easily wrapped/coated on negatively charged MWCNTs [33].…”

Recent advances in biological detection with magnetic nanoparticles as a useful tool

“…Luo et al [40] have demonstrated an effective ICP-MS-based multiplex and ultrasensitive assay of viruses with lanthanide-coded oligonucleotide hybridization and rolling circle amplification (RCA) strategies on biofunctional magnetic nanoparticles (MNPs) (Figure 1(b)). Single-stranded capture DNAfunctionalized MNPs were used for the separation of target [39]; (b) ICP-MS-based multiplex DNA assay with lanthanide-coded oligonucleotide hybridization strategy and biofunctional magnetic nanoparticle (MNP) enrichment [40]; (c) the sandwich DNA hybridization assay and the experimental procedure for the detection of target ssDNA strands using a SERS liquid chip (SLC) method [47]; (d) steps involved in the construction and function of the HRP/ChO x /GA-MNP/PDDA/MWCNT/GCE biosensor [53].…”

“…Eguilaz et al [53] have designed a novel biosensing electrode surface that combines the advantages of magnetic ferrite nanoparticles functionalized with glutaraldehyde (GA) and poly(diallyldimethylammonium chloride) (PDDA)-coated multiwalled carbon nanotubes (MWCNTs) as platforms for the construction of high-performance multienzyme biosensors (Figure 1(d)). A detection limit of 0.85 µmol/L for cholesterol was achieved, which was advantageously compared with the analytical characteristics of other CNT-based cholesterol biosensors.…”

Acetylcholinesterase Biosensor Based on Poly (diallyldimethylammonium chloride)-multi-walled Carbon Nanotubes-graphene Hybrid Film

“…PDDA-MWCNTs-GR hybrid was prepared according to the literatures with minor modifications [33,43]. 2 mg of MWCNTs and GR (3:1, MWCNTs:GR) were dispersed into 4 ml of 0.25% PDDA aqueous solution (containing 0.5 M NaCl) by sonication.…”