Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Genefine L. Sapateh - Clark Atlanta University
Co-Author(s): Amrit Sharma and Ian Stubbs, Clark Atlanta University, GA
Electroactive nanofibers decorated with functional groups that specifically interact with biomarkers have tremendous potential to be utilized as single molecule detectors. Previous investigations in our group used functionalized and proccessable electronic conductive polythiophenes to study polymer-biomarker interactions. Another approach is to use normally insulating polymer and mix it with single wall carbon nanotubes (SWCNT) to obtain a functional conductive composite. The advantages of using these composite nanostructures include good electrical sensitivity and biocompatibility because of their sizes related to biomolecules. Fabrication of electroactive composites into nanofibers have shown to be effective not only as carriers of therapeutic agents but also as the active component is biosensor. Nanofibers can be conveniently prepared by electrospinning. Variables affecting the quality of nanofibers include polymer molecular weight, polymer type, and solution viscosity. The molecular weight, concentration, and microphase separation in the nanofibers contributes to the overall physical characteristics of the nanofibers. In this study, we used a thermoplastic elastomeric triblock copolymer as an additive to prepare nanofibers with significantly improved physical properties. The triblock copolymer poly(styrene)-b-poly(dimethylsiloxane)-b-poly(styrene) (PS-b-PDMS-b-PS) was synthesized by living anionic polymerization. Each block was 10K in molecular weight. A solution with PS-b-PDMS-b-PS /PS at a w/w ratio of 1:5 in DMF along with SWCNT at 1% wt. was electrospun onto a silicon wafer at a flow rate of 20µl/min and a potential of 10kV. The fibers were characterized by SEM. Current-voltage (I-V) plots of the fibers were determined using a four-point probe and the I-V plots suggest that the fiber may be used as single molecule sensors. A solution with PS 900,000 Mw/SWCNT (100:1) was also spun for comparison with the fiber prepared using the triblock copolymers. The studies suggest that better quality fibers are obtained by using triblock copolymers.
Funder Acknowledgement(s): The support of this study NSF CREST HRD-1137751 is gratefully acknowledged.
Faculty Advisor: Ishrat Khan, email@example.com
Role: My part of research involved synthesizing the triblock and formulation of the composite through solution blend techniques. Then processing the composite through manipulation of a electrospinning setup. Characterization methods were also carried out on the material which included IR Spectroscopy, NMR, DSC, SEM, and AFM.