title: Aptamer-conjugated bio-bar-code Au-Fe3O4 nanoparticles as amplification station for electrochemiluminescence detection of tumor cells.
abstract: An electrochemiluminescence (ECL) assay has been developed for highly sensitive and selective detection of tumor cells based on cell-SELEX aptamer-target cell interactions through a cascaded amplification process by using bio-bar-code Au-Fe3O4 as amplification station. Firstly, bio-bar-code toehold-aptamer/DNA primer/Au-Fe3O4 (TA/DP/Au-Fe3O4) nanoconjugates are fabricated with a ratio of 1:10 to efficiently avoid cross-linking reaction and recognize target cells, which are immobilized on the substrate by hybridizing aptamer to capture probe with 18-mer. Through strand displacement reaction (SDR), the TA/DP/Au-Fe3O4 composites further act as the amplification station to initiate rolling circle amplification (RCA). As a result, on the surface of TA/DP/Au-Fe3O4, a large number of Ru(bpy)2(dcbpy)NHS-labeled probes hybridize to RCA products, which are easily trapped by magnetic electrode to perform the magnetic particle-based ECL platform. Under isothermal conditions, this powerful amplification strategy permits detection of Ramos cells as low as 16 cells with an excellent selectivity. Moreover, analysis of Ramos cells in complex samples and whole blood samples further show the great potential of this ultrasensitive approach in clinical application involving cancer cells-related biological processes.
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042, China; Laboratory of Fiber Materials and Modern Textiles, the Growing Base for State Key Laboratory, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China. Electronic address: bisai11@126.com.
authors.forename: Sai
authors.initials: S
authors.lastname: Bi
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042, China.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Jia
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042, China.
authors.forename: Peng
authors.initials: P
authors.lastname: He
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D045744:Cell Line, Tumor; D018914:Cells, Immobilized; D058893:DNA Barcoding, Taxonomic; D055664:Electrochemical Techniques / Q000379:methods*; D005290:Ferric Compounds; D017612:Gold Compounds; D006801:Humans; D049449:Luminescence; D060328:Magnetic Phenomena; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D009369:Neoplasms / Q000175:diagnosis*
chemical_list: D052157:Aptamers, Nucleotide; D005290:Ferric Compounds; D017612:Gold Compounds; C000499:ferric oxide
keywords: Bio-bar-code magnetic particles; Electrochemiluminescence; Rolling circle amplification; Strand displacement reaction; Tumor cells