title: Synthesis of AS1411-aptamer-conjugated CdTe quantum dots with high fluorescence strength for probe labeling tumor cells.
abstract: In this paper, we report microwave-assisted, one-stage synthesis of high-quality functionalized water-soluble cadmium telluride (CdTe) quantum dots (QDs). By selecting sodium tellurite as the Te source, cadmium chloride as the Cd source, mercaptosuccinic acid (MSA) as the capping agent, and a borate-acetic acid buffer solution with a pH range of 5-8, CdTe nanocrystals with four colors (blue to orange) were conveniently prepared at 100 °C under microwave irradiation in less than one hour (reaction time: 10-60 min). The influence of parameters such as the pH, Cd:Te molar ratio, and reaction time on the emission range and quantum yield percentage (QY%) was investigated. The structures and compositions of the prepared CdTe QDs were characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, selective area electron diffraction, and X-ray powder diffraction experiments. The formation mechanism of the QDs is discussed in this paper. Furthermore, AS1141-aptamer-conjugated CdTe QDs in the U87MG glioblastoma cell line were assessed with a fluorescence microscope. The obtained results showed that the best conditions for obtaining a high QY of approximately 87% are a pH of 6, a Cd:Te molar ratio of 5:1, and a 30-min reaction time at 100 °C under microwave irradiation. The results showed that AS1141-aptamer-conjugated CdTe QDs could enter tumor cells efficiently. It could be concluded that a facile high-fluorescence-strength QD conjugated with a DNA aptamer, AS1411, which can recognize the extracellular matrix protein nucleolin, can specifically target U87MG human glioblastoma cells. The qualified AS1411-aptamer-conjugated QDs prepared in this study showed excellent capabilities as nanoprobes for cancer targeting and molecular imaging.
authors.affiliation: Biotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, P.O.Box 9196773117, Mashhad, Iran.
authors.forename: Mona
authors.initials: M
authors.lastname: Alibolandi
authors.forename: Khalil
authors.initials: K
authors.lastname: Abnous
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ramezani
authors.forename: Hossein
authors.initials: H
authors.lastname: Hosseinkhani
authors.forename: Farzin
authors.initials: F
authors.lastname: Hadizadeh
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry*; D045744:Cell Line, Tumor; D005453:Fluorescence; D006801:Humans; D057054:Molecular Imaging / Q000379:methods*; D015335:Molecular Probes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009369:Neoplasms / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D045663:Quantum Dots; D013194:Staining and Labeling; D013691:Tellurium / Q000737:chemistry*
chemical_list: C513936:AGRO 100; D052157:Aptamers, Nucleotide; D019187:Cadmium Compounds; D015335:Molecular Probes; D009838:Oligodeoxyribonucleotides; D013691:Tellurium; C028337:cadmium telluride