title: DNA-templated silver nanoclusters based label-free fluorescent molecular beacon for the detection of adenosine deaminase.
abstract: A general and reliable fluorescent molecular beacon is proposed in this work utilizing DNA-templated silver nanoclusters (AgNCs). The fluorescent molecular beacon has been employed for sensitive determination of the concentration of adenosine deaminase (ADA) and its inhibition. A well-designed oligonucleotide containing three functional regions (an aptamer region for adenosine assembly, a sequence complementary to the region of the adenosine aptamer, and an inserted six bases cytosine-loop) is adopted as the core element in the strategy. The enzymatic reaction of adenosine catalyzed by ADA plays a key role as well in the regulation of the synthesis of the DNA-templated AgNCs, i.e. the signal indicator. The intensity of the fluorescence signal may thereby determine the concentration of the enzyme and its inhibitor. The detection limit of the ADA can be lowered to 0.05 UL(-1). Also, 100 fM of a known inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride (EHNA) is enough to present distinguishable fluorescence emission. Moreover, since the fluorescent signal indicator is not required to be bound with the oligonucleotide, this fluorescent molecular beacon may integrate the advantages of both the label-free and signal-on strategies.
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China; Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.forename: Minhao
authors.initials: M
authors.lastname: Xie
authors.forename: Xue
authors.initials: X
authors.lastname: Zhu
authors.forename: Lan
authors.initials: L
authors.lastname: Xu
authors.forename: Runlin
authors.initials: R
authors.lastname: Yang
authors.forename: Biao
authors.initials: B
authors.lastname: Huang
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhu
mesh_terms: D000243:Adenosine Deaminase / Q000737:chemistry / Q000302:isolation & purification*; D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D057230:Limit of Detection; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D052157:Aptamers, Nucleotide; D012834:Silver; D004247:DNA; D000243:Adenosine Deaminase
keywords: Adenosine deaminase; Aptamer; Complex biological fluids; Enzyme; Inhibitor; Silver nanoclusters