4 results about "DNA single strand" patented technology

The application belongs to the technical field of biosensing and specifically relates to a biosensor for detecting active acetylcholinesterase and application thereof. The biosensor comprises nanotubes with nanometer apertures at tips for generating current blocking signals; and a ring bundle DNA tetrahedron carrier for loading a solution containing active acetylcholinesterase to be detected, wherein the ring bundle DNA tetrahedron carrier is TDN1 or TDN4, the sequences of the four DNA single strands in TDN1 are shown as SEQ ID NO. 1 to SEQ ID NO. 4, and the sequences of the four DNA single strands in TDN4 are shown as SEQ ID NO. 1, SEQ ID NO. 3, SEQ ID NO. 5 and SEQ ID NO. 6. The application utilizes a closed-loop DNA tetrahedron nanostructure anchored at two ends of an aptamer to generate a difference in current signals in a nanometer hole before and after the active AChE is combined, so that high-sensitivity and high-selectivity detection of the active AChE at a single-molecule level is achieved.

This invention belongs to the field of biomedical technology, specifically relating to a DNA hydrogel with a kissing hairpin cross-linking structure, its preparation method, and its applications. The first end of the DNA single strand is connected to a first sticky end carrying a nucleic acid aptamer that specifically recognizes TNF-α, and the second end is connected to a second sticky end. The two hairpin structures form an integrated hairpin structure through complementary base pairing at their sticky ends. The loop regions of multiple integrated hairpin structures are cross-linked through complementary base pairing to form a DNA hydrogel with a three-dimensional network backbone. This application utilizes the self-assembly of anti-TNF-α nucleic acid aptamers to form a hydrogel via DNA kissing hairpin cross-linking, achieving controllable drug release. Compared to various TNF-α monoclonal antibodies and fusion protein biopharmaceuticals, anti-TNF-α nucleic acid aptamers offer the advantages of both good targeting and low cost; the self-assembly of the hydrogel via DNA kissing hairpin cross-linking allows for a wider range of adjustable release and higher safety.

The application belongs to the technical field of biological medicine. More specifically, it relates to a preparation and application of in-situ imaging DNA-PROTAC based on strand displacement activation. The novel DNA-PROTAC provided by the application is designed by three modules, which are respectively recruitment module A (E3 ligase ligand-linker-clicking group), locking module B (aptamer-shielded chain double-stranded complex) and activation module C (DNA single strand), three physically separated components, so that the degradation activity is completely silent in the delivery stage. Only after the drug reaches the target area, the in-situ assembly of recruitment module A and locking module B can be triggered by adding activation module C to trigger the strand displacement reaction, thereby effectively avoiding the non-specific activity of traditional degrading agents in the whole body circulation, and significantly reducing the off-target toxicity. In addition, the application converts the large conjugate into multiple independent components with medium and small molecular weights by physical splitting, overcoming the macromolecular delivery barrier.

This invention discloses a molecular switch-type nucleic acid framework fluorescent probe and its application in the detection of ATP molecules, a biomarker for depression, belonging to the field of biodetection technology. The fluorescent probe of this invention has a tetrahedral structure, comprising three complementary DNA single strands and four additional DNA single strands forming the tetrahedral structure. The three complementary DNA single strands include a Cy3 dye modified with a central backbone, a phosphate group modified at the 5' end, and a Cy5 dye modified at the 3' end. The fluorescent probe of this invention is activated by ATP, rapidly responding to ATP to emit a fluorescent signal, and is deactivated by an endonuclease, automatically returning to its initial state. This probe enables dynamic cyclic detection of ATP molecules and can directly perform rapid, highly sensitive, and highly selective quantitative analysis of the purine neurotransmitter ATP in complex biological samples such as plasma and urine, providing an effective means for early screening of neurological diseases.