5 results about "Nuclease" patented technology

The invention discloses a preparation method of a paper-based photocathode biosensor for detecting microRNA. A gold nano-particle layer is coated in a working area of a paper-based carbon working electrode; polyhedral cuprous oxide is electrodeposited and lots of silver sulfide quantum dots can be loaded, and a photoelectric sensitized structure is formed, so that the cathode photocurrent is increased substantially; and in the presence of the target microRNA, a double-strand-specific-nuclease-induced target cycle reaction and a cascaded stem-branch hybridization strand reaction are made to obtain a negatively charged dendritic DNA double-helix structure. After assembling of positively charged gold nanoparticles, a gold tree with the good glucose oxidase mimicking activity is formed, so that the glucose oxidation reaction is catalyzed, the dissolved oxygen of the electron acceptor is consumed, the cathode photocurrent signal is reduced, and sensitive detection of the microRNA is realized.

A pharmaceutical composition for treating cancer, containing a crRNA and an endonuclease as active ingredients is disclosed. The composition can be customized according to the needs of patients or cell types by specifically treating cancer cells on the basis of specific binding properties of DNA and RNA. The nuclease activity of a CRISPR PLUS system, containing both an endonuclease and an exonuclease can be activated by means of the binding between crRNA and a gene specifically found in cancer cells. Therefore, the cancer treatment effect of the composition is more specific than that of other anti-cancer agents that have been developed up till now.

The invention discloses a biosensing detection system for detecting ctDNA and a detection method thereof. The biosensing detection system comprises a spherical nucleic acid reporter, an RCA product and a CRISPR/Cas12a system, wherein the spherical nucleic acid reporter is a gold nanoparticle modified by a sulfydryl DNA chain; the RCA product is a product obtained by carrying out RCA amplification reaction on the ctDNA of the object to be detected and the 5 '-phosphorylated linear padlock probe; the CRISPR/Cas12a system comprises a stable binary complex formed by the LbCas12a protein and the crRNA (Complementary Ribonucleic Acid). The SNA provided by the invention has excellent nuclease cutting resistance in a physiological environment. Therefore, the SNA reporter is used for replacing the ssDNA reporter, so that the stability of the CRISPR/Cas12a system can be improved; rolling circle amplification (RCA) has the advantages of simplicity in operation, mild reaction temperature, high amplification efficiency and the like, and the RCA is combined with a CRISPR/Cas12a system, so that the sensitivity of the system can be remarkably improved.