title: Selective collection and detection of MCF-7 breast cancer cells using aptamer-functionalized magnetic beads and quantum dots based nano-bio-probes.
abstract: A novel strategy for selective collection and detection of breast cancer cells (MCF-7) based on aptamer-cell interaction was developed. Mucin 1 protein (MUC1) aptamer (Apt1) was covalently conjugated to magnetic beads to capture MCF-7 cell through affinity interaction between Apt1 and MUC1 protein that overexpressed on the surface of MCF-7 cells. Meanwhile, a nano-bio-probe was constructed by coupling of nucleolin aptamer AS1411 (Apt2) to CdTe quantum dots (QDs) which were homogeneously coated on the surfaces of monodispersed silica nanoparticles (SiO2 NPs). The nano-bio-probe displayed similar optical and electrochemical performances to free CdTe QDs, and remained high affinity to nucleolin overexpressed cells through the interaction between AS1411 and nucleolin protein. Photoluminescence (PL) and square-wave voltammetric (SWV) assays were used to quantitatively detect MCF-7 cells. Improved selectivity was obtained by using these two aptamers together as recognition elements simultaneously, compared to using any single aptamer. Based on the signal amplification of QDs coated silica nanoparticles (QDs/SiO2), the detection sensitivity was enhanced and a detection limit of 201 and 85 cells mL(-1) by PL and SWV method were achieved, respectively. The proposed strategy could be extended to detect other cells, and showed potential applications in cell imaging and drug delivery.
authors.affiliation: State Key Laboratory of Bioelectronics, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Hua
authors.forename: Zhenxian
authors.initials: Z
authors.lastname: Zhou
authors.forename: Liang
authors.initials: L
authors.lastname: Yuan
authors.forename: Songqin
authors.initials: S
authors.lastname: Liu
mesh_terms: D052157:Aptamers, Nucleotide; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation / Q000295:instrumentation / Q000379:methods*; D057230:Limit of Detection; D061986:MCF-7 Cells; D018396:Mucin-1 / Q000235:genetics / Q000378:metabolism; D049329:Nanostructures; D009838:Oligodeoxyribonucleotides; D010750:Phosphoproteins / Q000378:metabolism; D045663:Quantum Dots; D016601:RNA-Binding Proteins / Q000378:metabolism; D012822:Silicon Dioxide; D000097796:Nucleolin
chemical_list: D052157:Aptamers, Nucleotide; D018396:Mucin-1; D009838:Oligodeoxyribonucleotides; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D012822:Silicon Dioxide; D000097796:Nucleolin; C513936:AGRO 100; C060192:MUC1 protein, human
keywords: Aptamer; Aptamer–cell interaction; Breast cancer cells; Quantum dots; Signal amplification