▎ 摘　　要

NOVELTY - A fluorescent biosensor comprises graphene quantum dot and carboxymethyl cellulose-chitosan polyelectrolyte microsphere with core-shell structure, where the core is made up of melamine and formaldehyde and shell is made up of chitosan and carboxymethyl cellulose. USE - Fluorescent sensor for use in detection of chondroitin sulfate (claimed). ADVANTAGE - The fluorescent sensor has better market application prospect and industrial production value and improveddetection methods. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for preparing a fluorescent biosensor.