Based On The ECL Quantum Dots Research And Application Of New Biosensor About Energy Transfer

Since the end of the twentieth century, based on the unique and excellent propertiesof nanomaterials, the researchers developed a considerable number of new biologicalsensors. Semiconductor nanocrystals have wide application in the field of optical,electronic and biology research. Electrochemiluminescence biosensor has a lot ofadvantages, such as high sensitivity, simple instrumentation,wide linear range andautomation and so on. So it is more and more attractive to researchers. In this paper, thepreparation of many new ECL functional nanomaterials was studied, andelectrochemiluminescence biosensors were developed for the detection of DNA, cancercells and antigen.The following three main parts of this thesis can be studied:1. Water-soluble CdSe quantum dots with good ECL signals were firstlysynthesized. Through excellent film-forming characteristics of dendriticmacromolecules, dendritic quantum dots nanocompound modified electrodes wereprepared. Based on ECL quenching of novel folic acid to the nanocompound, the methodfor sensitive detection of target DNA using DNA cycling amplification technology wasdeveloped. PAMAM-CNT was used to assemble CdSe quantum dots, so the amountsand stability of CdSe quantum dots were improved, and ECL signal was amplified. TheECL signal is proportional to the concentration of target DNA in the range of1000 nmol L1to0.05nmol L1. The DNA detection limit was0.05nmol L1.2. We prepared a new electrochemiluminescent signal probe using a smallbifunctional composite quantum dot (QD) with intense electrochemiluminescence (ECL)and excellent magnetic property, and developed a sensitive ECL biosensor for detectionof cancer cells via DNA cyclic amplification technique. The graphene oxide with uniqueelectrical properties was used as nano-amplified platform to immobilize a large numberof capture DNA (c-DNA1). Specifically, the bifunctional composite QDs with excellentmagnetic property can be conveniently labeled, separated, and developed the ECL signalprobe, thus an ECL method for rapid and sensitive detection of cancer cells wasdeveloped. The detection limit was equivalent to100cells·mL-1, suggesting that thisstrategy is highly sensitive and has great potential for early and accurate detection ofcancer cells.3. In this study, we prepared the novel protein-like silver cysteine hybridnanowires with good reactivity and high load capacity. A large number of quantum dotsand antibody were loaded on the nanowires by a series of chemical reaction to developthe silver nano-cluster-quantum dots ECL probe. Based on the specific sandwichreaction strategy, after the primary antibody was linked to the antigen, the nano-cluster-quantum dots ECL probe reacted with the antigen, thus the sensitive detection of Agconcentration was conducted..