▎ 摘　　要

NOVELTY - Composition comprises: an aptamer hairpin probe comprising an aptamer and trigger-1 base sequence that specifically binds to a target substance; a first hairpin probe comprising a nucleotide sequence complementary to the trigger-1 nucleotide sequence, a G-rich nucleotide sequence, and a trigger-2 nucleotide sequence; and a second hairpin probe comprising a nucleotide sequence complementary to the trigger-1 nucleotide sequence, the G-rich nucleotide sequence, and the trigger-2 nucleotide sequence. USE - The composition is used for detecting a target substance, and is used for a kit for detecting a target material. The composition is used for detecting epithelial cells (all claimed). The composition is used for visualization of epithelial cell evidence. ADVANTAGE - Compared with a conventional aptamer-based target material detection method, the target material detection method enables easier and less expensive detection of a target material under various reaction conditions, and a hairpin probe not involved in the reaction is adsorbed by introducing graphene oxide to it, and a non-specific hybridization chain reaction can be more effectively prevented than a conventional hybridization chain reaction. The target material detection method is more stable than the conventional aptamer-based target material detection method using nanoparticles and enzymes, and has the advantage that it is possible to detect the target material more cheaply and conveniently without restrictions on various reaction conditions. The target material detection method does not require immobilization of a fluorescent material-modified nucleic acid probe, fluorescent material labeling, or an enzyme amplifying nucleic acid, and detection is possible with enzyme-free and label-free methods, and is significant in that non-specific reactions can be dramatically prevented by adsorbing hairpin probes that do not participate in the reaction using graphene oxide. The target material detection method has excellent versatility because it can target all substances detectable by aptamers such as metal ions. The composition is capable of detecting epithelial cells with high specificity and sensitivity, and the kit is capable of detecting a target material with high specificity and sensitivity. The composition can further contribute to the development of forensic investigation. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a kit for detecting a target material comprising the above-mentioned composition; (2) a method for detecting a target substance using a hybrid chain reaction, comprising (a) subjecting the target material to a hybrid chain reaction with the above-mentioned composition, and (b) measuring the G-quadruplex structure formed by the hybrid chain reaction; (3) a composition for detecting epithelial cells, comprising an aptamer hairpin probe comprising an aptamer and trigger-1 base sequence that specifically binds to an epithelial cell protein, a first hairpin probe comprising a nucleotide sequence complementary to the trigger-1 nucleotide sequence, a G-rich nucleotide sequence, and a trigger-2 nucleotide sequence, a second hairpin probe comprising a nucleotide sequence complementary to the trigger-1 nucleotide sequence, the G-rich nucleotide sequence, and the trigger-2 nucleotide sequence, and Thioflavin T (ThT); and (4) a method for detecting epithelial cells comprising reacting an epithelial cell-containing sample with the composition for detecting epithelial cells.