title: An enzyme-free strategy for ultrasensitive detection of adenosine using a multipurpose aptamer probe and malachite green.
abstract: We report on an enzyme-free and label-free strategy for the ultrasensitive determination of adenosine. A novel multipurpose adenosine aptamer (MAAP) is designed, which serves as an effective target recognition probe and a capture probe for malachite green. In the presence of adenosine, the conformation of the MAAP is converted from a hairpin structure to a G-quadruplex. Upon addition of malachite green into this solution, a noticeable enhancement of resonance light scattering was observed. The signal response is directly proportional to the concentration of adenosine ranging from 75 pM to 2.2 nM with a detection limit of 23 pM, which was 100-10,000 folds lower than those obtained by previous reported methods. Moreover, this strategy has been applied successfully for detecting adenosine in human urine and blood samples, further proving its reliability. The mechanism of adenosine inducing MAAP to form a G-quadruplex was demonstrated by a series of control experiments. Such a MAAP probe can also be used to other strategies such as fluorescence or spectrophotometric ones. We suppose that this strategy can be expanded to develop a universal analytical platform for various target molecules in the biomedical field and clinical diagnosis.
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Hui
authors: H
authors: Zhao
authors: College of Public Health, University of South China, Hengyang, 421001, PR China. Electronic address: yongsheng.w@tom.com.
authors: Yong-Sheng
authors: YS
authors: Wang
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Xian
authors: X
authors: Tang
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Bin
authors: B
authors: Zhou
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Jin-Hua
authors: JH
authors: Xue
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Hui
authors: H
authors: Liu
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Shan-Du
authors: SD
authors: Liu
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Jin-Xiu
authors: JX
authors: Cao
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Ming-Hui
authors: MH
authors: Li
authors: College of Public Health, University of South China, Hengyang, 421001, PR China.
authors: Si-Han
authors: SH
authors: Chen
mesh_terms: D000241:Adenosine / Q000032:analysis / Q000097:blood* / Q000652:urine*; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D004396:Coloring Agents / Q000737:chemistry*; D054856:G-Quadruplexes; D006801:Humans; D057230:Limit of Detection; D008969:Molecular Sequence Data; D015203:Reproducibility of Results; D012394:Rosaniline Dyes / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; D004396:Coloring Agents; D012394:Rosaniline Dyes; C005095:malachite green; D000241:Adenosine
keywords: Adenosine; Malachite green; Multipurpose aptamer probe; Ultrasensitive detection; Urine and blood samples