Study Of Electrochemiluminescence Biosensor Based On Qds Composites

Electrochemiluminescence analysis biosensor has a lot of advantages,such as high sensitivity, simple instrumentation, fast, wide linear rangeand automatic and so on, So it is more and more attractive to researchers.In this paper, electrochemiluminescence biosensors are developed basedon QDs composites, realizing high effective detection of ATP, thrombinand Ramos cells.The following three main parts of this thesis can be studied:1we fabricated a highly electrochemiluminescent, fluorescent andmagnetic dendrimeric QDs nanocomposite, and successfully used thenanocomposite for sensitive ATP detection based on ECL quenching byGNPs using cycle amplification technique. The ECL signal was proportional to the ATP concentration in the range from1.0×10^-8mol L^-1to8.0×10^-7mol L^-1. The detection limit for ATP concentration wascalculated to be3.09×109mol L^-1.2we have prepared a novel small multifunctional composite QD withintense ECL, excellent magnetism, strong fluorescence, and developed aDNA-amplified method for sensitive thrombin assay based on ECLquenching of the composite QDs by gold NPs. The ΔI was found to belogarithmically related to the thrombin concentrations in the range from1.0pM to5.0nM （R=0.994） with a detection limit of0.12pM.3we fabricated a novel dendritic, magnetic andelectrochemiluminescent QDs nanocomposites, and successfully appliedthem to the cancer cells assays based on ECL quenching of QDsnanocomposite by gold NPs. The magnetic QDs nanocomposites can bedirectly used to perform DNA conjugation, gold NPs linking and sensingtarget cells, which is more rapid, convenient, complete and has betterreproducibility than the conventional ECL reagents. This strategy opens a new class of multifunctional QD nanocomposites for ECL assay of cancercells, which has promising applications for the early clinical detection ofcancer.