title: Unimolecular catalytic DNA biosensor for amplified detection of L-histidine via an enzymatic recycling cleavage strategy.
abstract: Fluorescence catalytic beacons have emerged as a general platform for sensing applications. However, almost all such sensing systems need covalent modification of the DNAzymes with fluorophore-quencher pairs, which may require elaborate design of the synthetic routes and many heavy and complicated synthetic steps and result in increased cost and lower synthesis yield. Here we report the construction of fluorescent cascadic catalytic beacons. With separation of the molecular recognition module from the signal reporter, this new design both avoids DNAzyme modifications and improves sensitivity through an endonuclease-based cascadic enzymatic signal amplification. This allows detection of L-histidine with high sensitivity (LOD = 200 nM) and excellent specificity. The proposed sensing system has also been used for detection of L-histidine in cellular homogenate with satisfactory results.
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Rong-Mei
authors.initials: RM
authors.lastname: Kong
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Zhang
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Chen
authors.forename: Hong-Min
authors.initials: HM
authors.lastname: Meng
authors.forename: Zhi-Ling
authors.initials: ZL
authors.lastname: Song
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Shen
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu
mesh_terms: D015374:Biosensing Techniques; D002384:Catalysis; D021881:DNA, Catalytic / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000737:chemistry; D006639:Histidine / Q000032:analysis*; D021141:Nucleic Acid Amplification Techniques; D009693:Nucleic Acid Hybridization
chemical_list: D021881:DNA, Catalytic; D005456:Fluorescent Dyes; D006639:Histidine