Polyaniline Nanofibers as Chemiresistive Transducers: Seeded Synthesis, Characterization and DNA Sensing

In this paper, seeded synthesis of Polyaniline (PANi) nanofibers, their characterization and use as transducers in chemiresistive DNA sensing have been reported. PANi, among many one-dimensional conductive polymers, has shown great potential as a transducer in chemiresistive biosensing in general and DNA sensing in particular, on account of its natural conductivity, ease of doping and surface functionalization. Herein, PANi nanofibers were synthesized using a seeding method, using single walled carbon nanotube (SWCNT) seeds. Surface morphology of the thus synthesized nanofibers were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The nanofibers were surface modified with 2% glutaraldehyde for facilitating probe-DNA immobilization, and the results of the same were investigated using Fourier transform infrared spectroscopy. Further, towards analyzing the electrical transport properties of the PANi nanofibers, I-V characteristics were recorded in the applied bias range of −10 V - +10 V, using Agilent B1500A parametric analyzer. As inferred, the I-V response was symmetric about the vertical axis, revealing a crossover between near-Ohmic and power-law dominated regions. As a case study, in this work, the PANi nanofibers were used as transducers for chemiresistive detection of Dengue virus specific consensus primers (DENVCP).