title: An ultrasensitive supersandwich electrochemical DNA biosensor based on gold nanoparticles decorated reduced graphene oxide.
abstract: In this article, a supersandwich-type electrochemical biosensor for sequence-specific DNA detection is described. In design, single-strand DNA labeled with methylene blue (MB) was used as signal probe, and auxiliary probe was designed to hybridize with two different regions of signal probe. The biosensor construction contained three steps: (i) capture DNA labeled with thiol was immobilized on the surface of gold nanoparticles decorated reduced graphene oxide (Au NPs/rGO); (ii) the sandwich structure formation contained "capture-target-signal probe"; and (iii) auxiliary probe was introduced to produce long concatamers containing signal molecule MB. Differential pulse voltammetry (DPV) was used to monitor the DNA hybridization event using peak current changes of MB in phosphate-buffered saline (PBS) containing 1.0M NaClO4. Under optimal conditions, the peak currents of MB were linear with the logarithm of the concentration of target DNA in the range of 0.1μM to 0.1fM with a detection limit of 35aM (signal/noise=3). In addition, this biosensor exhibited good selectivity even for single-base mismatched target DNA detection.
authors.affiliation: College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, and Anhui Key Laboratory of Chemo-Biosensing, Anhui Normal University, Wuhu 241000, People's Republic of China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, and Anhui Key Laboratory of Chemo-Biosensing, Anhui Normal University, Wuhu 241000, People's Republic of China.
authors.forename: Anqi
authors.initials: A
authors.lastname: Shi
authors.affiliation: College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, and Anhui Key Laboratory of Chemo-Biosensing, Anhui Normal University, Wuhu 241000, People's Republic of China.
authors.forename: Xian
authors.initials: X
authors.lastname: Fang
authors.affiliation: College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, and Anhui Key Laboratory of Chemo-Biosensing, Anhui Normal University, Wuhu 241000, People's Republic of China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Han
authors.affiliation: College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, and Anhui Key Laboratory of Chemo-Biosensing, Anhui Normal University, Wuhu 241000, People's Republic of China. Electronic address: zhyz65@mail.ahnu.edu.cn.
authors.forename: Yuzhong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis*; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry
chemical_list: D010087:Oxides; D006046:Gold; D006108:Graphite; D004247:DNA
keywords: DNA biosensor; Differential pulse voltammetry; Gold nanoparticles; Reduced graphene oxide