| Electrochemiluminescence(ECL) is a newly developed analytical method based on chemiluminiscence. It combines the advantages of chemiluminiscence and electrochemical analysis, and has some new superiorities, such as high sensitivity and antijamming capability, good reproducibility, on-site analysis, and wide dynamic range. We explored the ECL performance of some new material, and build some ECL biosensor for the detection of cancer cell. In the manuscript, biological recognition technology and nanomaterial were applied for signal amplification1. A newly prepared [(ppy)2Ir(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 canavalin 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 sandwichtype ECL cytosensor showed a linear response to K562 cells at concentrations ranging from 1.0 × 102 to 1.0 × 106 cells/m L 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.2. A novel graphene family compounds(H-RGO-Au NRs) was first developed to establish the quantum dots electroluminescent immunosensors. H-RGO-Au NRs had a high efficient electro-catalytic property to H2O2, which was used as the co-reactant of the quantum dots(QDs) electroluminescent immunosensors. It was also demonstrated that H-RGO-Au NRs had a preferable electro-catalytic property than single grapheme and H-RGO. A mass of Au NRs in the compound of H-RGO-Au NRs, had an effective electroluminescent energy transfer with Cd S:Eu quantum dots. Based on all the above, a novel ultrasensitive electroluminescent immunosensor was built for the carcino-embryonic antigen(CEA) detection. To embody the signal ampli?cation property of the protocol, the performance of various labels was compared in detail. The immunosensor displayed excellent analytical performance for the detection of CEA range from 0.01 pg/m L to 1.0 ng/m L with a detection limit of 0.01 pg/m L, and the resulting immunosensor also showed high sensitivity, good reproducibility and stability.3. A ternary composite of hemin-reduced graphene oxide-Au nanoparticles(H-RGO-Au) is synthesized through π-π interaction for hemin-graphene hybrid nanosheets and then hydrogen tetracholoroauric acid is reduced in situ by Na BH4 and ascorbic acid. This ternary composite shows a higher electrocatalytic activity for the reduction of hydrogen peroxide than that of hemin-graphene components, which could act as an catalyst to produce sensitive ECL quenching of QDs due to the electrocatalytic reduction of H2O2, the ECL coreactant. With the use of the H-RGO-Au catalyst with high loading of concanavalin A(Con A), which could specifically recognize and bind to mannose or the core trimannoside of N-glycans on the cell surface, a novel ultrasensitive cytosensing for cancer cells detection was proposed. This proposed method could sensitively detect K562 cells with a linear calibration range from 4.8 × 102 to 5.0 × 105 cells/m L. Since the Con A can specifically recognize and bind to mannose or the core trimannoside of N-glycans on the cell surface, the designed strategy has an expansive application for the construction of versatile ECL cytosensing platforms. |
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