title: Enhanced iridium complex electrochemiluminescence cytosensing and dynamic evaluation of cell-surface carbohydrate expression.
abstract: A newly prepared [(ppy)2 Ir(dcbpy)](+) ⋅PF6 (-) (ppy: 2-phenylpyridyl; dcbpy: 4,4'-dicarboxy-2,2'-bipyridyl) and gold nanoparticle functionalized mesoporous silica nanoparticle (Au/Ir-MSN) is reported. Based on the binding between concanavalin A (Con A) and mannose, the novel nanoparticle was applied to an ultrasensitive electrochemiluminescence (ECL) in situ cytosensing strategy and the dynamic evaluation of cell-surface carbohydrate expression. The ECL activity of the presented Con A@Au/Ir-MSN nanoprobe was greatly enhanced by employing a functionalized nanoparticle and graphene nanomaterial with an increased surface area and simultaneously improved electron-transfer efficiency at the electrode interface. Under optimal conditions, the sandwich-type ECL cytosensor showed a linear response to K562 cells at concentrations ranging from 1.0×10(2) to 1.0×10(6)  cells mL(-1) and realized a low detection limit of a single cell. The proposed method could also be successfully used for monitoring the dynamic variation of carbohydrate expression in cancer cells in response to external stimulation by an inhibitor.
authors.affiliation: School of Chemistry and Chemical Engineering of Linyi University, Linyi 276005 (P. R. China).
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
authors.forename: Yiying
authors.initials: Y
authors.lastname: Yang
authors.forename: Chunxiang
authors.initials: C
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Yu
authors.forename: Shusheng
authors.initials: S
authors.lastname: Zhang
mesh_terms: D002241:Carbohydrates / Q000032:analysis / Q000096:biosynthesis*; D056831:Coordination Complexes / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D006801:Humans; D007495:Iridium / Q000737:chemistry*; D020014:K562 Cells; D008163:Luminescent Measurements / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D056831:Coordination Complexes; D007495:Iridium
keywords: biosensors; electrochemiluminescence; gold; iridium; nanoparticles