The Detection Of MicroRNAs In Hepatocellular Carcinoma Markers By Photochemical Sensors Based On Quantum Dots And MoS₂

Cancer is a serious threat to human health and frequently pathogenesis,and livercancer is the world's third most common and cancer-related disease.The discovery of tumor markers has brought great changes in the diagnosis and treatment of cancer.A large part of tumor markers belong to microRNAs(mi RNAs).Therefore,the high sensitivity and high selectivity of miRNAs detection are particularly important.In this paper,the tumor markers of liver cancer were detected by resonant light scattering and fluorescence spectroscopy using resonance light scattering signals and fluorescence properties of quantum dots(QDs).In addition,MoS2 as a fluorescent quencher for the detection of liver cancer markers also obtained a good results.The main contents are as follows:1.We designed a simple RLS biosensor to detect the sensitivity and selectivity of miRNA-122 by designing a CdTe QDs-P probe.The effects of DNA coverage on the surfaces of QDs for RLS system were investigated.The effects of time,temperature and particle concentration on the RLS of the system were also investigated.Under the optimal experimental conditions,the change of RLS intensity(?IRLS)has a good linear relationship with the target miRNA-122 in the range of 0.10 nM to 4.80 nM.In the absence of cyclic amplification,the detection limit of miRNA-122 Reached 9.4pM.This program was finally successfully applied to serum sample spiked recovery experiments.2.Owe to the photostability and larger Stokes red shift of QDs,core-shell CdTe@CdS QDs were synthesized to high sensitivity and selectivity simultaneously detect two tumor markers.Under the optimal experimental conditions,the change of fluorescence intensity(?F)has a good linear relationship with the target miRNA-122 in the range of 5 nM to 270 nM.?F and the target miRNA-99a/b-3p concentration in the range of 10 nM to 350 nM have a good linear relationship.This method was successfully applied to serum samples of spiked recovery experiments and different cell lysates on miRNA detection experiments.3.The hepatoma tumor marker miRNA-199a/b-3p high sensitivity and high selectivity detection were achieved by combining HCR technique with G-quadruple structure by using MoS2 to adsorb single-chain and fluorescence quenching properties.The influence of the various conditions on the fluorescence signal in the reaction system was investigated.In addition,the introduction of the monolayer MoS2 nanosheets greatly reduced the background signal of the system and further amplified the fluorescence signal.The concentration of miRNA-99a/b-3p in the range of 0.1 nM to 100 nM was better than that of the target miRNA-99a/b-3p.The detection of miRNA-199a/b-3p was 5.9 pM.This program was successfully applied to serum samples of spiked recovery experiments and cell lysates on miRNA detection experiments.