title: Visual detection of cancer cells by colorimetric aptasensor based on aggregation of gold nanoparticles induced by DNA hybridization.
abstract: A simple but highly sensitive colorimetric method was developed to detect cancer cells based on aptamer-cell interaction. Cancer cells were able to capture nucleolin aptamers (AS 1411) through affinity interaction between AS 1411 and nucleolin receptors that are over expressed in cancer cells, The specific binding of AS 1411 to the target cells triggered the removal of aptamers from the solution. Therefore no aptamer remained in the solution to hybridize with complementary ssDNA-AuNP probes as a result the solution color is red. In the absence of target cells or the presence of normal cells, ssDNA-AuNP probes and aptamers were coexisted in solution and the aptamers assembled DNA-AuNPs, produced a purple solution. UV-vis spectrometry demonstrated that this hybridization-based method exhibited selective colorimetric responses to the presence or absence of target cells, which is detectable with naked eye. The linear response for MCF-7 cells in a concentration range from 10 to 10(5) cells was obtained with a detection limit of 10 cells. The proposed method could be extended to detect other cells and showed potential applications in cancer cell detection and early cancer diagnosis.
authors.affiliation: Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.
authors.forename: Yasaman-Sadat
authors.initials: YS
authors.lastname: Borghei
authors.affiliation: Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran. Electronic address: smhosseini@khayam.ut.ac.ir.
authors.forename: Morteza
authors.initials: M
authors.lastname: Hosseini
authors.affiliation: Payame Noor University, Tehran, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Dadmehr
authors.affiliation: Department of Biochemistry, Tarbiat Modares University, Tehran, Iran.
authors.forename: Saman
authors.initials: S
authors.lastname: Hosseinkhani
authors.affiliation: Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran, Iran; Biosensor Research Center, Endocrinology & Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ganjali
authors.affiliation: Department of Molecular Biology, Tofigh Daru Co., Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Sheikhnejad
mesh_terms: D002151:Calorimetry / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles; D009369:Neoplasms / Q000175:diagnosis*; D009693:Nucleic Acid Hybridization
chemical_list: D006046:Gold; D004247:DNA
keywords: Aptamer; Cancer cells; Colorimetric; Gold nanoparticles; Nucleolin