Paper TF+BI-ThA10
Electronic Characterization of SWCNT/Block Copolymer-based Nanofiber for Biosensor Application

Thursday, November 10, 2016, 5:20 pm, Room 104E

The aim of this research is to fabricate an electrically conducting, smooth, continuous and sensitive nanofiber using polystyrene (PS), triblock copolymer (PS-b-PDMS-b-PS) and single-walled carbon nanotubes (SWCNTs) by electrospinning. The electronic nanofibers may be utilized for effective bio-sensing applications. The SWCNTs have been of great interest to researchers because of their exceptional electrical, mechanical, and thermal properties. The nanoscale diameter, high aspect ratio, and low density make them an ideal reinforcing candidate for novel nano composite material.

Electrically conducting nanofibers have been prepared by electrospinning a solution of PS, PS-b-PDMS-b-PS and functionalized SWCNTs in the ratio 5:1:0.05 using solvent DMF. The nanofibers formed had an average diameter of 5 µm and height 4 µm. These nanofibers were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), optical microscopy and electrical characterization.

The electrical characterization of a single fiber shows an almost linear graph of current vs voltage using four-point probe (also known as Kelvin sensing) method. This linear graph exemplifies the conducting nature of the nanofiber. From the graph, a resistance, resistivity and conductivity of the single were measured. The study suggests that the SWCNT/block copolymer nanofibers have superior performance in the development of ultra-high sensitive sensor for the detection of single molecule relative to conventional materials due to significantly larger surface-to-volume ratio. Future work includes preparing nanofibers decorated with functional groups and binding with specific type of enzyme or protein to study their I-V behavior. This approach or method can be utilized for bio-sensing activities, especially for the detection of various antibodies and protein molecules.

References:

[1] Ramakrishna, S.; Fujihara, K.; Teo, W.-E.; Lim, T.-C.; Ma, Z. An Introduction to Electrospinning and Nanofibers; World Scientific: Singapore, 2005.

[2] Charlier, J.-C.; Issi, J.-P. Electrical Conductivity of Novel Forms of Carbon. Journal of Physics and Chemistry of Solids. 1996, 57, 957–965.

[3] Zhao, B.; Hu, H.; Haddon, R. C. Synthesis and Properties of a Water-Soluble Single-Walled Carbon Nanotube–Poly (m-Amino benzene Sulfonic Acid) Graft Copolymer. Advanced Functional Materials. 2004, 14, 71–76.

Funder Acknowledgement(s): This research was funded and supported by the National Science Foundation, CREST, DMR-0934142 and the Center for Functional Nanoscale Material Research program at Clark Atlanta University.

Faculty Advisor/ Mentor: Dr. Michael D. Williams, mdwms@cau.edu