Guanine oxidation signal enhancement in single strand DNA with polyacrylonitrile/polyaniline (PAN/PAni) hybrid nanofibers

Abstract

Pure polyacrylonitrile (PAN) and polyacrylonitrile/polyaniline (PAN/PAni) hybrid nanofibers (NFs) were produced via electrospinning and used to monitor guanine oxidation in single strand DNA (ssDNA) by electrochemical methods. Two different methodologies were conducted. First, pre‐synthesized PAni was added into electrospinning PAN solution and electrospun into composite PAN/PAni nanofibrous structure on cylindrical pencil graphite (PGE) surface. In the second route, PAN NFs were electrospun on a PGE surfaces and polymerization of PAni was conducted on the surfaces of the as‐spun PAN NFs. NFs were kept at −18 °C in a refrigerator for several days. ssDNA was immobilized on the prepared NFs and guanine oxidation signals were observed for each system. The results revealed that use of PAN NFs enhanced signal intensity from 0.92 µA (PGE) to 1.04 µA (PAN NFs). Addition of PAni to PAN increased signal intensity to 1.23 µA. When the PAN NF surfaces were coated with PAni, signal enhancement continued to increase up to 4.19 µA for fourth day and decreased again when PAni‐coated NFs were kept at −18 °C in the refrigerator. Since the prepared system is fast and cheap, it is promising for application in DNA biosensor devices. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45567.

Guanine oxidation signal amplification in single strand DNA molecules with heat‐treated polyacrylonitrile/sulfuric acid micro/nanofibrous system

“…Electrospun pure cellulose monoacetate nanofibers were also examined by Bostancı et al for the detection of guanine oxidation of the ssDNA molecules and 1.69 μA signal intensity was measured 48 . In another study, guanine oxidation of the ssDNA molecules was measured with pure PAN nanofibers as 1.04 μA and polyaniline loaded PAN nanofibers as 1.04 μA 26 . On the other hand, the signal was measured as 4.19 μA when PAN was coated with PANI 26 .…”

“…In another study, guanine oxidation of the ssDNA molecules was measured with pure PAN nanofibers as 1.04 μA and polyaniline loaded PAN nanofibers as 1.04 μA 26 . On the other hand, the signal was measured as 4.19 μA when PAN was coated with PANI 26 . The conductive nature of polyaniline must have enhanced signal intensity.…”

“…Synthetic ssDNA molecules (5′‐GTT CAC GTG TAT GTT GAG‐3′) were immobilized on the final treated micro/nanofiber coated PGEs via physical adsorption method. The same procedure as Cam et al reported was applied for ssDNA immobilization 26 . ssDNA molecules that could not adhere to the surface were removed by washing with Tris‐buffered saline (TBS) solution.…”

“…With electro attraction technology, high amounts of nanofibers can be produced from many materials such as polymers, ceramics, carbon, and composites 23‐25 . PAN nanofibers have been produced by the electrospinning method as neat and with addition and used as precursors for the prediction of carbon nanofibers in various fields such as biosensor, energy storage, etc 26‐28 …”

“…Electrodes used in biosensors have been modified with various nanomaterials to enhance the oxidation signal in electrochemical measurements 33 . The detection of the guanine oxidation signal by coating PAN nanofibers on the graphite electrode surfaces was reported by Tanik et al 34 The use of PAN/PANI composite nanofibers to observe the guanine oxidation signal has been studied by Cam et al 26 …”