Construction Of Functional Fluorescence Nanocomposite Probe And Its Application In Bioanalysis

Cancer and other major diseases are a global medical problem that seriously threatens human health.the best way to prevent and cure cancer is early diagnosis,early treatment,accurate and rapid analysis and detection of disease-related biomolecules.it can reflect the development of the disease in time and provide a scientific basis for the diagnosis of diseases,which is of great significance in the early warning and clinical treatment of many major diseases.The construction of a highly sensitive and selective biochemical sensing analysis system to achieve accurate and rapid detection of low concentration targets in complex biological matrix has become an urgent practical demand and research focus.Based on a variety of functional nanomaterials,different fluorescent nano-sensing systems are designed and constructed in this paper.On the one hand,the accurate detection and photothermal therapy of many different types of tumor markers are realized,on the other hand,the highly sensitive detection of tumor marker c-MYC is realized by using near-infrared controllable signal amplification technology.The main research work is as follows:(1)Based on the fluorescence resonance energy transfer(FRET)sensing strategy,an integrated multi-functional fluorescent nanoprobe with accurate diagnosis and treatment was constructed by using two different fluorescent color gold nanoclusters(Au NCs)modified by single-stranded DNA as energy donors and polydopamine-coated gold nanocones(Au NBPs@PDA)as energy receptors.To achieve simultaneous detection of two different types of tumor markers(MUC1 and mi RNA-21)in single cell under single wavelength excitation and photothermal therapy of tumor cells.The fluorescence intensity at 515 nm and 620 nm increases gradually with the increase of target concentration of mi RNA-21 and MUC1,and the fluorescence intensity recovered at 515 nm is linear with the concentration of mi RNA-21 in the range of 0.05～50 n M,and the detection limit is 18 p M.The fluorescence intensity recovered at 620 nm has a linear relationship with the concentration of MUC1 in the range of 0.5～25 n M,and the detection limit is 0.17 n M.After 808 nm near-infrared light irradiation,Au NBPs@PDA converts light energy into heat energy,achieving a cancer cell killing efficiency of 71.75%.The multi-functional integrated nanoprobe we constructed not only realizes the simultaneous detection of many different types of tumor markers,but also realizes the photothermal treatment of cancer.it provides an effective auxiliary means for the early accurate diagnosis and treatment of cancer and other major diseases.(2)By introducing the up-conversion optical control technology into the traditional catalytic hairpin self-assembly signal amplification strategy,a new spatio-temporal controllable signal amplification detection method activated by near-infrared light is designed and constructed,and the spatio-temporal controllable and highly sensitive detection of intracellular tumor marker c-MYC is realized.In this strategy,we designed and synthesized molecular beacons containing UV-degradable molecules(PC-linker),modified them to the surface of upconversion nanoparticles that can convert near-infrared light into ultraviolet light by electrostatic interaction,and used 808 nm near-infrared light to realize the remote activation of its sensor recognition function.Compared with the traditional 980 nm near-infrared light,the 808 nm near-infrared light used in this strategy eliminates the overheating effect in the biological tissue and avoids the thermal damage to the local biological tissue.This new method of signal amplification and detection activated by 808 nm near infrared light provides a new idea for the time-space controllable accurate imaging detection of intracellular tumor markers,and shows important scientific research value and application prospect in the field of precision medical detection.