title: Detection of femtomolar level osteosarcoma-related gene via a chronocoulometric DNA biosensor based on nanostructure gold electrode.
abstract: In this paper, a sensitive chronocoulometric deoxyribonucleic acid (DNA) biosensor based on a nanostructure gold electrode was fabricated for detection of the femtomolar level survivin gene which was correlated with osteosarcoma by using hexaamine-ruthenium III complexes, [Ru(NH(3))(6)](3+), as the electrochemical indicator. The effect of different frequencies on the real surface area of the nanostructure gold electrode obtained by repetitive square-wave oxidation reduction cycle was investigated. At the optimal frequency of 8000 Hz, the real surface of the developed nanostructure gold electrode was about 42.5 times compared with that of the bare planar gold electrode. The capture probe DNA was immobilized on the nanostructure gold electrode and hybridized with target DNA. Electrochemical signals of hexaamine-ruthenium III bound to the anionic phosphate of DNA strands via electrostatic interactions were measured by chronocoulometry before and after hybridization. The increase of the charges of hexaamine-ruthenium III was observed upon hybridization of the probe with target DNA. Results indicate that this DNA biosensor could detect the femtomole (fM) concentration of the DNA target quantitatively in the range of 50 fM to 250 fM; the detection limit of this DNA biosensor was 5.6 fM (signal to noise = 3). This new biosensor exhibits excellent sensitivity and selectivity and has been used for an assay of polymerase chain reaction (PCR) with a satisfactory result.
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou, People’s Republic of China.
authors.forename: Guangxian
authors.initials: G
authors.lastname: Zhong
authors.forename: Ailin
authors.initials: A
authors.lastname: Liu
authors.forename: Xiongwei
authors.initials: X
authors.lastname: Xu
authors.forename: Zhouliang
authors.initials: Z
authors.lastname: Sun
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Chen
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Qicai
authors.initials: Q
authors.lastname: Liu
authors.forename: Xinhua
authors.initials: X
authors.lastname: Lin
authors.forename: Jianhua
authors.initials: J
authors.lastname: Lin
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D001859:Bone Neoplasms / Q000737:chemistry / Q000235:genetics*; D004273:DNA, Neoplasm / Q000032:analysis* / Q000737:chemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*; D012516:Osteosarcoma / Q000737:chemistry / Q000235:genetics*; D017975:Ruthenium Compounds; D000077022:Survivin
chemical_list: C107489:BIRC5 protein, human; D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D051034:Inhibitor of Apoptosis Proteins; D017975:Ruthenium Compounds; D000077022:Survivin; C031584:hexammineruthenium; D006046:Gold