Fabrication of electroactive composite nanofibers of functionalized polymer and CNT capable of specifically binding with the IgE (Immunoglobulin E) antibody

Abstract

Electroactive nanofibers decorated with a,v-bi-(dinitrophenylcaproic acid), abbreviated as DNP, have been prepared by electrospinning a solution of a,v-bi [2,4-dinitrophenylcaproic][poly(ethyleneoxide)-b-poly(2-methoxystyrene)-b-poly (ethylene oxide)], polystyrene and single-walled carbon nanotubes (SWCNTs). The a,v-bi [2,4-dinitrophenylcaproic] [poly(ethyleneoxide)-b-poly(2-methoxystyrene)-b-poly(ethyleneoxide)] polymers were synthesized by living anionic polymerization and subsequent esterification to obtain the DNP-functionalized polymers. The nanofibers (300 nm) were electrospun onto a silicon wafer substrate at a voltage of 10 kV using dimethylformamide and chlorobenzene as solvents. The nanofibers were characterized by Raman spectroscopy, fluorescence microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical microscopy. The DNP groups, therein, were tethered to the nanofibers via oligo(oxyethylene) spacers. The DNP groups decorating the nanofibers were capable of specifically binding with anti-DNP immunoglobulin E (IgE). The binding specificity of nanofibers containing 1% SWCNTs with anti-DNP IgE was studied via fluorescently labeled (Fluorescein IsoThioCyanate) FITC-IgE. Electronic activity of the nanofibers was studied by I-V plots from Kelvin sensing. The I-V plots before sensitizing with IgE differed from the I-V plots after binding with IgE. The results of the studies suggest the possibility of developing functional nanofibers as the active component in biosensors.

Study on the AFM Force Curve Common Errors and Their Effects on the Calculated Nanomechanical Properties of Materials

“…The Hertz model can also be used to calculate Young's modulus of a material from its indentation force curve. Based on this model the sample is assumed to be linear in its elasticity and an isotropic solid, and the indenter is considered as a rigid material [27,33]. Most studies have used the approach part of the force curve to calculate Young's modulus [5,6,33]; however, the average value of the approach-retract portion has also been considered [11].…”

“…Based on this model the sample is assumed to be linear in its elasticity and an isotropic solid, and the indenter is considered as a rigid material [27,33]. Most studies have used the approach part of the force curve to calculate Young's modulus [5,6,33]; however, the average value of the approach-retract portion has also been considered [11]. For the four-sided pyramid indenter used in AFM, the Hertz model for calculating Young's modulus utilized the following [34]:…”

“…where is the face angle of the cantilever and is Poisson's ratio of the sample. For the Berkovich three-sided indenter used in the NTS, the Hertz model for calculating Young's modulus utilized the following [33,35]:…”

Fabrication of Bioactive Surfaces by Functionalization of Electroactive and Surface-Active Block Copolymers

“…Surface accessibility of ligands is crucial to receptors, whether in drug delivery systems or diagnostics. Antigen-antibody characteristic of DNP-IgE has been tested in our group with a synthesized block copolymers α,ω-bi(2,4-dinitrophenyl caproic) (poly(ethyleneoxide)-b-poly(2-methoxystyrene)b-poly(ethylene oxide)) [16,21]. Block copolymers contains at least two polymer blocks which phase separate into two or more immiscible phase domains within the polymeric region.…”

Nanofibras eletrofiadas de poliamida 6 e polialilamina hidroclorada funcionalizadas com nanotubos de carbono e nanopartículas de ouro aplicadas em sensores e biossensores

“…A utilização das nanofibras pode ser ampliada explorando-se os grupos químicos funcionais nos polímeros utilizados na eletrofiação, alterando-se sua superfície com métodos químicos ou físicos. Isso permite incorporar outros tipos de materiais, como nanotubos de carbono [6], nanopartículas metálicas [7,8], nanopartículas de óxidos metálico, complexos organo-metálicos [9] e moléculas biológicas (enzimas, anticorpos, ácidos nucleicos e bactérias) [10][11][12]. Com essa modificação superficial, podem ser combinadas propriedades desses materiais com as das nanofibras, resultando em nanocompósitos com funcionalidades variadas.…”