A Sensitive DNA Biosensor Using Graphene Oxide as the Multi-Site Platform for Probe DNA Immobilization

Abstract

An ultrasensitive DNA biosensor was constructed in this work by using graphene oxide nanosheets (GONs) as the multi-site platform for probe DNA immobilization. First, L-cysteine (L-cys) was self-assembled on a gold electrode surface based on the Au-S chemistry. Then the GONs and amino modified probe DNA was covalently grafted to L-cys/AuE surface in turn, with the aid of 1-(3-Dimethylanminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-Hydroxy succinimide (NHS). The layer upon layer assembly process was characterized with atomic force microscopy and electrochemical methods. Due to the nano-size effect and multiple site characteristic of GONs, the immobilization density of the probe DNA was determined to be as high as 5.72 × 10 −10 mol cm −2 using methylene blue as the redox probe. The hybridization experiments showed that the biosensor can quantitatively detect target DNA in a wide range from 1.0 × 10 −15 M to 1.0 × 10 −9 M with a detection limit of 5.0 × 10 −16 M. The selectivity experiments showed that the sensing system could accurately discriminate the complementary sequence from the base mismatched and non-complementary sequences.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 202.118.73.220 Downloaded on 2015-08-21 to IP B292Journal of The Electrochemical Society, 162 (12) B291-B297 (2015) ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 202.118.73.220 Downloaded on 2015-08-21 to IP Journal of The Electrochemical Society, 162 (12) B291-B297 (2015) B297 potential of the developed biosensor to meet the inexpensive, rapid, and handy detection of DNA in real samples.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 202.118.73.220 Downloaded on 2015-08-21 to IP

An Electrochemical Nanogenosensor for Label Based and Label Free Detection of H. Pylori cagE Gene and Evaluation of DNA Damage Induced by UVC Radiation

“…Graphene (GR), as a new class of one-atom thick and two-dimensional carbon material, has been intensively investigated in recent years due to its unique structure and properties, such as large surface area, high electrical conductivity, mechanical strength, ease of functionalization, and mass production. 7 The unique sp 2 hybrid carbon nanostructure of GR opens up novel applications in sensing [8][9][10][11][12] and energy storage. [13][14][15] GR can be prepared by two distinct methods; that is, top-down and bottom-up.…”