title: An electrochemical aptasensor based on hybridization chain reaction with enzyme-signal amplification for interferon-gamma detection.
abstract: A novel electrochemical aptasensor based on hybridization chain reaction (HCR) with enzyme-signal amplification was constructed for the detection of interferon-gamma (IFN-γ). In this aptasensor, the recognition probes which contained the sequence of IFN-γ aptamer were initially binded to IFN-γ, and the unbound recognition probes were captured on the electrode as an initiator to trigger the HCR. The two DNA hairpins bio-H1 and bio-H2 were opened by the recognition probe, and bound one by one on the electrode. The biotin was used as a tracer in the hairpins and streptavidin-alkaline phosphatase (SA-ALP) as a reporter molecule. Then, SA-ALP converted its electro-inactive substrate 1-naphthyl phosphate into an electroactive derivative 1-naphthol generating amplified electrochemical signal by differential pulse voltammetry (DPV). The activity of the immobilized enzyme was voltammetrically determined by measuring the amount of 1-naphthol generated for enzymatic dephosphorylation of 1-naphthyl phosphate. The electrochemical signal observed was inversely related to the concentration of IFN-γ. The proposed approach showed a high sensitivity for IFN-γ in a concentration range of 0.5-300 nM with a detection limit of 0.3 nM. The sensing system also provided satisfactory results for the detection of IFN-γ in the cell media.
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Jingjin
authors.initials: J
authors.lastname: Zhao
authors.forename: Chunfei
authors.initials: C
authors.lastname: Chen
authors.forename: Liangliang
authors.initials: L
authors.lastname: Zhang
authors.forename: Jianhui
authors.initials: J
authors.lastname: Jiang
authors.forename: Ruqin
authors.initials: R
authors.lastname: Yu
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000737:chemistry; D015342:DNA Probes / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry; D007371:Interferon-gamma / Q000032:analysis*; D057230:Limit of Detection; D009281:Naphthalenes / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry; D019809:Streptavidin / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D015342:DNA Probes; D004800:Enzymes, Immobilized; D009281:Naphthalenes; D009943:Organophosphorus Compounds; C014694:naphthyl phosphate; D001710:Biotin; D007371:Interferon-gamma; D019809:Streptavidin; D000469:Alkaline Phosphatase