title: Fluorescent oligonucleotide probe based on G-quadruplex scaffold for signal-on ultrasensitive protein assay.
abstract: This work reported the G-quadruplex structure of pyrene-labeled G-rich DNA probe and its application in the immunoglobulin E (IgE) detection, providing plausibly an insight into the biological function of human telomere. Based on the intermolecular G-quadruplex, a terminal-single-pyrene-labeled oligonucleotide signaling probe was developed and a novel protein assay strategy was proposed via combining specific DNA cleavage by S1 nuclease with target-recognizing aptamer. This assay platform not only circumvented the optimization of specific sites for reporter attachment and the pyrene monomer fluorescence quenching by flanking nucleotide bases but also presented a signal-on mechanism. Thus, ultrasensitive homogeneous detection of IgE was successfully conducted. A linear dynamic range of 4.72 x 10(-12) to 7.56 x 10(-9)m, a regression coefficient of 0.9941 and a detection limit of 9.45 x 10(-14)m were given. Additionally, a preliminary concept of the single-pyrene-labeled excimer fluorescence probes associated with G-quadruplex for screening biological markers was described. Importantly, the unexpected structural property of G-quadruplex discovered seems to provide valuable information to allow understanding of the structure and function of human telomere and exploring of useful structure-based anticancer drug.
authors: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, PR China. wuzaisheng@163.com
authors: Zai-Sheng
authors: ZS
authors: Wu
authors: Peng
authors: P
authors: Hu
authors: Hui
authors: H
authors: Zhou
authors: Guoli
authors: G
authors: Shen
authors: Ruqin
authors: R
authors: Yu
mesh_terms: D052158:Aptamers, Peptide / Q000378:metabolism; D001681:Biological Assay / Q000379:methods*; D015374:Biosensing Techniques; D005456:Fluorescent Dyes / Q000378:metabolism*; D054856:G-Quadruplexes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007073:Immunoglobulin E / Q000378:metabolism*; D008954:Models, Biological; D009841:Oligonucleotides / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013997:Time Factors
chemical_list: D052158:Aptamers, Peptide; D005456:Fluorescent Dyes; D009841:Oligonucleotides; D007073:Immunoglobulin E