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Electrochemiluminescent Determination of Cancer Cells Based on Aptamers, Nanoparticles, and Magnetic Beads
Author(s) -
Ding Caifeng,
Wei Shuang,
Liu Haitao
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201104019
Subject(s) - nanoprobe , aptamer , electrochemiluminescence , detection limit , linker , magnetic nanoparticles , conjugated system , dna , cancer cell , chemistry , materials science , nanoparticle , nanotechnology , microbiology and biotechnology , cancer , chromatography , biochemistry , polymer , biology , genetics , computer science , operating system , organic chemistry
Herein we report a polymerase chain reaction (PCR)‐free electrochemiluminescence (ECL) approach that uses ECL nanoprobes for the determination of cancer cells with high sensitivity. The ECL nanoprobe consists of gold nanoparticles (AuNPs), linker DNA, and tris(2,2′‐bipyridyl)ruthenium (TBR)‐labeled signal DNA. The linker DNA and signal DNA were modified on the surface of the AuNPs through AuS bonds. The linker DNA can partly hybridize with the aptamers of cancer cells loaded onto the magnetic beads (MB 1 ) to construct the magnetic biocomplexes. In the presence of the cancer cells, the aptamers conjugated with the cancer cells with higher affinity. The ECL nanoprobe was released from the biocomplexes and subsequently hybridized with the capture DNA loaded onto another magnetic bead (MB 2 ) to form the magnetic nanocomposite. The nanocomposites can be easily separated and firmly attached to an electrode on account of their excellent magnetic properties. The ECL intensity of the TBR loaded onto the nanocomposites directly reflected the amount of cancer cells. By using cell lines of Burkitt’s lymphoma (Ramos cells) as a model, the ECL response was proportional to the cell concentration in the range from 5 to 100 cells ml −1 ; a limit of detection as low as 5 cells ml −1 of Ramos cells could be achieved. The proposed method described here is ideal for the diagnosis of cancers due to its high sensitivity, simplicity, and low cost.