▎ 摘　　要

NOVELTY - Biosensor comprises a nanocomplex (NC) including molybdenum disulfide, graphene and chitosan (CHT), and flower-shaped gold nanostructure (AuNF) in which reporter RNA (reRNA) is immobilized on arranged on an electrode. USE - The biosensor is useful in kit for detecting target RNA, preferably SARS-CoV-2 RNA (all claimed). ADVANTAGE - The biosensor detects a very small amount of target RNA with high sensitivity and high accuracy without a nucleic acid amplification reaction through the CRISPR/Cas13a trans-cleavage reaction, minimizes test time, and performs on-site diagnostic test for RNA-based infectious diseases that spread rapidly. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: a method (M1) for preparing the biosensor involves (a) sequentially arranging the nanocomplex and the flower-shaped gold nanostructure on an electrode, and (b) immobilizing reRNA tagged with a redox molecule to the electrode on which the nanocomplex and nanostructure are arranged; a method (M2) for detecting target RNA using the biosensor involves processing clustered regularly interspaced short palindromic repeats (CRISPR) associated protein (Cas) 13a-CRISPR RNA (crRNA)-RNA mixed sample in the biosensor, and measuring the reduced amount of current of the biosensor; and a kit comprising the biosensor, Cas13a, and a target RNA-specific crRNA. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram for fabricating biosensor. AuNFFlower-shaped gold nanostructure NCNanocomplex SPCEScreen-printed carbon electrode