title: Enzyme-free and label-free ultrasensitive electrochemical detection of human immunodeficiency virus DNA in biological samples based on long-range self-assembled DNA nanostructures.
abstract: Biosensors based on nanomaterials have been used for detection of various biological molecules with high sensitivity and selectivity. Herein, we developed a simple and ultrasensitive electrochemical DNA biosensor using long-range self-assembled DNA nanostructures as carriers for signal amplification, which can achieve an impressive detection limit of 5 aM human immunodeficiency virus (HIV) DNA even in complex biological samples. In this study, we designed two auxiliary probes. A cascade of hybridization events between the two auxiliary probes can lead to long-range self-assembly and form micrometer-long one-dimensional DNA nanostructures. In the presence of target DNA, each copy of the target can act as a trigger to connect a DNA nanostructure to a capture probe on the electrode surface. Then, a great amount of redox indicator [Ru(NH(3))(6)](3+) can be electrostatically bound to the DNA nanostructures and eventually result in significantly amplified electrochemical signals.
authors.affiliation: The Key Lab of Analysis and Detection Technology for Food Safety of the MOE, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Chen
authors.forename: Cheng-Yi
authors.initials: CY
authors.lastname: Hong
authors.forename: Ya-Hui
authors.initials: YH
authors.lastname: Lin
authors.forename: Jing-Hua
authors.initials: JH
authors.lastname: Chen
authors.forename: Guo-Nan
authors.initials: GN
authors.lastname: Chen
authors.forename: Huang-Hao
authors.initials: HH
authors.lastname: Yang
mesh_terms: D015374:Biosensing Techniques; D004279:DNA, Viral / Q000032:analysis*; D055664:Electrochemical Techniques; D004566:Electrodes; D015497:HIV-1 / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D049329:Nanostructures / Q000032:analysis*
chemical_list: D004279:DNA, Viral