Preparation Of Multifunctional Nanoprobes And Their Applications In Biochemical Analysis

At present, cancer is one of the main diseases which threatened people’s healthseriously. The cure rate is low and the recurrence rate is high in the process of thediagnosis and treatment. Clinical studies found that early diagnosis and timelytreatment is one of the effective means to improve the survival rate of cancer patients,and an imoptant technology for highly sensitive detection of tumor cell is developed inorder to achieve the early detection of cancer. In the field of clinical medicine, targetedanti-cancer drugs and early diagnosis is recognized as the world’s best solution to forthe treatment of tumors currently. In this paper, a series of probes that can specificallyrecognize tumor cells was designed which used nanotechnology and fluorescenceimaging technology, providing certain laboratory basis for the diagnosis of tumor cellsand the development of targeted drugs. The contents are as follows:1. A nanocapsule was prepared, which in gold cage as the core, internal loadinganticancer drug doxorubicin hydrochloride (DOX), functionalized DNA nanomaterialsfor the shell and blocked the mouth of the cage. The nanocapsule included celldetection, drug delivery and other functions, can be identified under the fluorescencemicroscope and detected the target cells (Ramos cells), while releasing the drug andacting on target cells, leading to cell death. Gold nanoparticles can be used as drugcarrier because of its good biocompatibility and empty structure. And fluorescentbackground interference is low because of the design of structure about fluorescentswitch.The probe can be used to track the process of drug release in real time due toDOX and DNAfluorescence switch.2. A novel modular functionalized DNA nano-probe was synthesized for cancercell imaging and detection of apoptosis or necrosis by redshift effect. The probe wasconstructed on the basis of a modular design of orderly assembling DNA-CdTequantum dot@AnnexinV nanoparticles and DNA aptamer sequences on DNAnanowire. With the enormous coverage of DNA-CdTe quantum dot@AnnexinVnanoparticles, the DNA nano-probe possessed high fluorescence intensity. Owing tothe high affinity and selectivity of the cell-binding DNA aptamer for its target cell, the DNA nano-probe can rapidly and specifcally bind to target cells. Furthermore, theDNAnano-probe can be applied in detection of apoptosis or necrosis by redshift effect.3. The design and preparation of DNA-CdTe/mesoporous SiO2fluorescentprobes are based on covalent binding of CdTe quantum dots and mesoporous SiO2.CdTe quantum dots have a strong fluorescent properties, the use of DNA aptamerstrand is the recognition sequence of Ramos cells，so this probes are very specific inthat each probe can recognize Ramos cells only, and can be used for observing Ramoscells by laser scanning confocal microscope. This work provides a theoretical basis inthe early detection of tumor cells.