▎ 摘　　要

NOVELTY - Graphene quantum dot complex (I) is new. USE - (I) is useful in preparing test solution for detecting calcium ions (claimed). ADVANTAGE - (I) has simple synthesis method, mild reaction conditions, readily available raw materials; and has light-emitting properties, good water-soluble properties. DETAILED DESCRIPTION - Graphene quantum dot complex of formula (I) is new. INDEPENDENT CLAIMS are also included for: (1) preparation of (I); and (2) use method of (I) in preparing test solution for detecting calcium ions comprising dissolving (I) in water or aqueous alcohol solution, where concentration of calcium ions in test solution is 0.05-3.0 mg/ml.