title: Design and implementation of electrochemical cytosensor for evaluation of cell surface carbohydrate and glycoprotein.
abstract: A new strategy for assessing cell surface carbohydrates and P-glycoprotein (P-gp) expression status and quantifying the cell numbers with an electrochemical immunoassay was designed. In order to construct the base of the cytosensor, a novel 3-D architecture was initially fabricated by combining nitrogen-doped carbon nanotubes, thionine, and gold nanoparticles via a simple layer-by-layer method. The formed architecture provided an effective matrix for concanavalin A (Con A) binding and made the immobilized Con A hold high stability and bioactivity. On the basis of the specific recognition of cell surface mannosyl groups to Con A, the Con A/3-D architecture interface showed a predominant capability for cell capture. With another coupled signal amplification based on a enzymatic catalytic reaction of HRP toward the oxidation of thionine by the H(2)O(2), which was induced by two-step immunoreactions, the proposed cytosensor showed an excellent analytical performance for the detection of HeLa cells ranging from 8.0 x 10(2) to 2.0 x 10(7) cells mL(-1) with a limit of detection of 500 cells mL(-1). Moreover, with the use of preblocking procedures, the mannosyl groups and P-gp on single HeLa cell could be further detected to be (4 +/- 2) x 10(10) molecules of mannose moieties and 8.47 x 10(6) molecules of P-gp. This strategy offers great promise for sensitive detection of cancer cells and cell surface receptors and thus may help improve cancer diagnosis and treatment.
authors.affiliation: Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Zhang
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Cheng
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Zheng
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Zhu
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000032:analysis / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002241:Carbohydrates / Q000032:analysis / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry; D010640:Phenothiazines / Q000737:chemistry
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D002241:Carbohydrates; D037742:Nanotubes, Carbon; D010640:Phenothiazines; D006046:Gold; C009469:thionine