Electrochemical DNA Biosensor Based on Partially Reduced Graphene Oxide Modified Carbon Ionic Liquid Electrode for the Detection of Transgenic Soybean A2704‐12 Gene Sequence

Abstract

In this work a partially reduced graphene oxide (p-RGO) modified carbon ionic liquid electrode (CILE) was prepared as the platform to fabricate an electrochemical DNA sensor, which was used for the sensitive detection of target ssDNA sequence related to transgenic soybean A2704-12 sequence. The CILE was fabricated by using 1-butylpyridinium hexafluorophosphate as the binder and then p-RGO was deposited on the surface of CILE by controlling the electroreduction conditions. NH 2 modified ssDNA probe sequences were immobilized on the electrode surface via covalent bonds between the unreduced oxygen groups on the p-RGO surface and the amine group at the 5'-end of ssDNA, which was denoted as ssDNA/p-RGO/CILE and further used to hybridize with the target ssDNA sequence. Methylene blue (MB) was used as electrochemical indicator to monitor the DNA hybridization. The reduction peak current of MB after hybridization was proportional to the concentration of target A2704-12 ssDNA sequences in the range from 1.0 10 À12 to 1.0 10 À6 mol/L with a detection limit of 2.9 10 À13 mol/L (3s). The electrochemical DNA biosensor was further used for the detection of PCR products of transgenic soybean with satisfactory results.

Electrochemical genoassays on gold-coated magnetic nanoparticles to quantify genetically modified organisms (GMOs) in food and feed as GMO percentage

“…In fact, other chronoamperometric genosensors performed directly on non-nanostructured Au electrodes reported a higher LOD of 225 pM (Liao et al 2013). Alternative electrochemical techniques such as CV, DPV or SWV with different electroactive probes added after hybridization reached LOD ranging from 22.5 nM (Ren et al 2005) to 0.290 pM (Sun et al 2013). The latter employed reduced graphene oxide as a platform for probe immobilization, which confirms that nanomaterials improve the analytical features in genoassays.…”

Aqueous ionic liquids in comparison with standard co-solutes

“…In the latter case, novel magnetic ILs turn out to be particularly interesting for the purpose of effective extraction and preservation of DNA (Clark et al 2015a(Clark et al , b, 2016. For industrial purposes, ILs are being currently applied in DNA-based biosensors (Chen et al 2013;Sun et al 2013;Machado et al 2014), or to assist a vast variety of methods in genetic manipulations, including genomic sequencing (Kulkarni and Mukherjee 2016), cloning (Li et al 2013b), or gene delivery and transformation (Zhang et al 2009;Soni et al 2015). Moreover, replacement of standard aqueous solutions by ILs as solvents and catalysts for laboratory purposes enabled to overcome certain technological limitations associated with DNA nanotechnology (Nishimura et al 2005;Dandia et al 2013) due to enhanced DNA stability and solubility in ILs (Zhang et al 2009;Sharma et al 2015;Jumbri et al 2016;Mishra et al 2016).…”

Facile Fabrication of DNA Biosensors Based on Oxidized Carbon Black and Graphite Oxide

“…GrO consists of graphene oxide sheets and displays oxygen-containing functional groups on the surface (alcohols, quinones, and carboxylic acids). As a consequence, GrO has a high potential to create a covalent bond between oxygen and amines [18][19][20].…”