The Synthezation Of Multifunctional Inorganic Nanocomposites And The Applicaitions In Electrochemiluminescence Biosensor

Nanomaterials,a series of novel nano-sized material with several unique qualities including surface and boundary effect,quantum size effect,and macroscopical quanta tunnel effect,have been widely employed in the field of electro-catalysis and biosensing.Nowadays,cancers,Alzheimer's disease?AD?and et al have threatened human's healthy and affected peoples' living quality.It was regretful that many patients who suffered with cancer or AD did not pay any attentions at the early stage of these diseases,and it was late when they felt uncomfortable.In order to avoid this tragedy,how to detect these diseases at early stage becomes a hot point for the researchers in biochemical field.In this work,we had prepared several novel nanomaterials and utilized these materials into electrochemiluminescence?ECL?biosensor for the sensitive detection of the biomarkers of cancer and AD,which was very significant.The ECL biosensor had attracted a lot of attention in biological and chemical field for its high sensitivity,superior selectivity and low background signal.Generally,some unique nanomaterials with large specific surface areas and superior catalytic abilities had been applied into the process of biosensor fabrication,which could improve the sensitivity and stability of the biosensor,leading the sensor become more significant and authentic.Encouraged by the advantages of nanomaterials in biosensor fabrication,we had synthesized some novel nanomaterials with excellent catalytic ability and utilized these nanomaterials into biosensor constration:1.Electrochemiluminescence immunosensor based on multifunctional luminol-capped AuNPs@Fe₃O₄ nanocomposite for the detection of mucin-1In this work,we had immobilized the ECL luminophere of luminol on the surface of nanomaterial,and synthesized a novel ECL nanocomposite of luminol capped AuNPs?Fe₃O₄?Lu-AuNPs@Fe₃O₄?.This ECL composite also had been applied as the nanocarrier of MUCl's secondary antibody?Ab2?,and then be used to construct a sandwich-type ECL immunosensor for MUC1 detection.Lu-AuNPs@Fe₃O₄ exhibited superior conductivity and excellent catalytic ability in H₂O₂ decomposition,which could further enhance the ECL intensity of luminol-H₂O₂ system.And Fe₃O₄ could be separated by magnet easily,which effectively simplified the process of MUC1 detection.Meanwhile,we had prepared non-toxicity AuNPs@ZnO nanomaterial as the carrier of anti-MUC1?Ab1?,this material could also promote the decomposition of H₂O₂ and enhance the ECL emitting,realizing the sensitive detection of MUC1.2.Ceria Doped Zinc Oxide Nanoflowers Enhanced Luminol-Based Electrochemiluminescence Immunosensor for Amyloid-? DetectionIn this work,the ECL luminophere of luminol was immobilized on ceria doped ZnO nanoflowers via amidation?Ce:ZONFs-Lum?.Ce:ZONFs-Lum displayed excellent activity in catalyzing the decomposition of H₂O₂,which could promote the ECL intensity of luminol.More notably,Ce3+/Ce4+ pair in Ce:ZONFs-Lum could switch reversibly and rapidly,which endowed high catalytic activity and electron-transfer rate,further enhanced the ECL signal of this immunosensor.Compared with our previous work,the amido linkage between Ce:ZONFs and luminol was more stable than Au-N bond between AuNPs and luminol,thus the ECL efficiency of Ce:ZONFs-Lum was further enhanced.The proposed ECL immunosensor presented wide linear range and low detection limit.3.Ru-complex modified DNA nanostructure-based self-enhanced ECL biosensor for the detection of mircoRNA141When somebody suffered with cancer,not only some specific proteins in his body expressed abnormality,but also some concentrations of specific DNA or RNA were aberrant.So,some DNAs or RNAs had been utilized as the biomarkers of cancer in early stage detection.Herein,we had constructed a Ru-based self-enhanced ECL biosensor for microRNA141 detection.Firstly,the reticular DNA nanostructure?NS?was assembled on PEI-SiO2 surface in situ.Then,we chose "light-switch" Ru-complex as the ECL luminophere and intercalated the molecule into DNA NS to obtain a self-enchanced ECL nanomaterials of Ru@DNA-PEI@SiO2.The ECL efficiency of the intercalated Ru complex was much stronger than that was in aqueous solution;and PEI was an ideal coreactant of Ru complex to futher increase the ECL intensity.The prepared ECL material was immobilized on sensing interface and emitted strong ECL signal,when the target of miRNA141 was incubated on the sensor,the DNA NS would disassemble and a large number of Ru complex would separate from sensing interface,indicating a remarkable decrease of the ECL signal,which realized the sensitive detection of miRNA141 with detect limit of 3.7 fmol/L.In this work,a strong ECL signal could be obtained in PBS only,attributing to the superior self-enhanced ECL nanomaterial,and the directly detecting method could simplified the detect process effectively,which proved a new and simple strategy for miRNA detection.