title: Fluorescein-labeled "arch-like" DNA probes for electrochemical detection of DNA on gold nanoparticle-modified gold electrodes.
abstract: In the present study, a gold nanoparticle-modified gold electrode (nanogold electrode) was used to develop a novel fluorescein electrochemical DNA biosensor based on a target-induced conformational change. The nanogold electrode was obtained by electrodepositing gold nanoparticles onto a bare gold electrode. This modification not only immobilized probe oligonucleotides, but also adsorbed fluorescein onto the surface of the gold nanoparticles to form an "arch-like" structure. This article compares the electrochemical signal changes caused by the hybridization of "arch-like" DNA on nanogold electrode and linear DNA on bare gold electrode. The results showed that the adsorption effect of nanogold can enhance the sensitivity of the sensor. The linear range of target ssDNA is from 2.0 × 10(-9)M to 2.0 × 10(-8)M with a correlation coefficient of 0.9956 and detection limit (3σ) of 7.10 × 10(-10)M. Additionally, the specificity and hybridization response of this simple sensor were investigated.
authors.affiliation: The Affiliated Hospital of Medical College Qingdao University, 266003, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.forename: Hao-ra
authors.initials: HR
authors.lastname: Su
authors.forename: Gui-Rong
authors.initials: GR
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Shang-jing
authors.initials: SJ
authors.lastname: Guo
authors.forename: Xiao-ru
authors.initials: XR
authors.lastname: Zhang
authors.forename: Shu-sheng
authors.initials: SS
authors.lastname: Zhang
authors.forename: Shi-chao
authors.initials: SC
authors.lastname: Xing
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D015342:DNA Probes / Q000737:chemistry* / Q000235:genetics; D004566:Electrodes; D019793:Fluorescein / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D012680:Sensitivity and Specificity
chemical_list: D015342:DNA Probes; D006046:Gold; D004247:DNA; D019793:Fluorescein
keywords: E-DNA sensor; Electrodeposition; Fluorescein; Gold nanoparticles