Boronic acid functionalized magnetic composites with sandwich-like nanostructures as a novel matrix for PDGF detection

Abstract

In this paper, we present a novel multifunctional magnetic composite with sandwich-like nanostructure, which is composed of a yolk-egg-like magnetic silica core and a continuous polydopamine(PDA)-Au coating. Firstly, yolk-egg-like magnetic composite(SiO 2 @Fe 3 O 4 @PDA) was prepared by a combined high temperature decomposition method with mussel chemistry.Then, Au nanoparticles(NPs) were in-situ generated on the surface of the SiO 2 @Fe 3 O 4 @PDA by reaction between the PDA shell and HAuCl 4 , forming a multilayer sandwich-like nanostructure.Benefiting from the good affinity of the PDA shell and Au NPs with thiol group, the 4-mercaptophenylboronic acid was successfully assembled on the surface of Au NPs and PDA layer. The hybrid magnetic composite functionalized with boronic acid was used as affinity probes to selectively capture PDGF from solution. Meanwhile, methylene blue(MB)-doped silica NPs (SiO 2 -MB) were prepared to immobilize aptamer. In the presence of PDGF, the aptamer labeled SiO 2 -MB (SiO 2 -MB-aptamer) specifically bound with the PDGF protein. By monitoring the change of the electrochemical signal of MB, we were able to detect the binding events between the aptamer and PDGF in homogeneous solutions. The sensor was highly selective and sensitive with a detection limit of 0.22 fM for PDGF. The developed method showed wide potential applications in protein monitoring and cancer diagnosis.

Aptamer-Modified Magnetic Beads in Biosensing

“…Zheng et al [ 59 ] have developed an assay based on aptamer-conjugated to methylene blue for the detection of human platelet-derived growth factor BB (PDGF-BB). In this work, boronic acid modified SiO 2 @Fe 3 O 4 @PDA@AuNP composite was used to capture PDGF-BB from the sample.…”

Rational design, synthesis, and applications of carbon-assisted dispersive Ni-based composites

“…48,49 PDA can be easily coated on different substrates and form controlled thin layers because of its adhesive properties. 48,50 Additionally, PDA can be easily obtained via the self-oxidation polymerization of dopamine at room temperature in an ethanol/water system under basic conditions (the Stöber conditions). 51,52 For example, a PDA thin layer was developed on various substrates with different morphologies with an extended Stöber method.…”

Electrochemical Aptasensor of Carcinoembryonic Antigen Based on Concanavalin A-Functionalized Magnetic Copper Silicate Carbon Microtubes and Gold-Nanocluster-Assisted Signal Amplification

“…In addition, coating with an immune reagent will hamper electron transfer, which greatly has an effect on the sensitivity. The utilization of magnetic supports as an alternative immobilization support can effectively solve these drawbacks and endow with these advantages, such as easy separation, no need for modification, improved sensitivity, and reduction of matrix effects. , Owing to the advantages of this strategy with no modification of the electrode as well as good performance for direct determination, more work has been done to magnetic electrodes coupled with functionalized magnetic composites.…”