▎ 摘　　要

NOVELTY - Preparation of covalent organic framework/graphene nanosheet composite material involves grafting 1,4-benzenediboronic acid on graphene nanosheets as a carrier, and vertically growing covalent organic framework on the carrier. USE - Preparation of covalent organic framework/graphene nanosheet composite material used as adsorbent for solid-phase extraction for enrichment and detection of trace amounts of o-hydroxy plant hormones (all claimed). ADVANTAGE - The method enables preparation of covalent organic framework/graphene nanosheet composite material with rich mesopores having high specific surface area. The composite material can increase the effective contact area with o-hydroxy plant hormones, and shorten the time required for pretreatment. The large amount of boric acid groups contained in 1,4-benzenediboronic acid can selectively enrich trace amounts of o-hydroxy plant hormones, and the large number of delocalized ( pi ) bonds, hydroxyl group and carboxyl groups can produce strong ( pi )-( pi ) interaction and hydrogen bond interaction, and enhance the selective enrichment effect of o-hydroxyl plant hormones.