title: A gold nanoparticle-based label free colorimetric aptasensor for adenosine deaminase detection and inhibition assay.
abstract: A novel strategy for the fabrication of a colorimetric aptasensor using label free gold nanoparticles (AuNPs) is proposed in this work, and the strategy has been employed for the assay of adenosine deaminase (ADA) activity. The aptasensor consists of adenosine (AD) aptamer, AD and AuNPs. The design of the biosensor takes advantage of the special optical properties of AuNPs and the interaction between AuNPs and single-strand DNA. In the absence of ADA, the AuNPs are aggregated and are blue in color under appropriate salt concentration because of the grid structure of an AD aptamer when binding to AD, while in the presence of the analyte, AuNPs remain dispersed with red color under the same concentration of salt owing to ADA converting AD into inosine which has no affinity with the AD aptamer, thus allowing quantitative investigation of ADA activity. The present strategy is simple, cost-effective, selective and sensitive for ADA with a detection limit of 1.526 U L(-1), which is about one order of magnitude lower than that previously reported. In addition, a very low concentration of the inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) could generate a distinguishable response. Therefore, the AuNP-based colorimetric biosensor has great potential in the diagnosis of ADA-relevant diseases and drug screening.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, and Wuhan Institute of Biotechnology, Wuhan University, Wuhan, 430072, P. R. China. hwtang@whu.edu.cn.
authors.forename: Fen
authors.initials: F
authors.lastname: Cheng
authors.forename: Yue
authors.initials: Y
authors.lastname: He
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Xing
authors.forename: Dai-Di
authors.initials: DD
authors.lastname: Tan
authors.forename: Yi
authors.initials: Y
authors.lastname: Lin
authors.forename: Dai-Wen
authors.initials: DW
authors.lastname: Pang
authors.forename: Hong-Wu
authors.initials: HW
authors.lastname: Tang
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000243:Adenosine Deaminase / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D058892:Adenosine Deaminase Inhibitors / Q000494:pharmacology; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001681:Biological Assay / Q000379:methods*; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*
chemical_list: D058892:Adenosine Deaminase Inhibitors; D052157:Aptamers, Nucleotide; D006046:Gold; D000243:Adenosine Deaminase; D000241:Adenosine