▎ 摘　　要

NOVELTY - Hybrid nanomaterial comprises graphene oxide nanomaterial covalently conjugated to cationic quaternized chitosan, where the cationic quaternized chitosan is (I). USE - The hybrid nanomaterial is useful in an antimicrobial composition which is used: for inhibiting growth of microorganisms in an environment, where the microorganisms are Gram-positive bacteria, Gram-negative bacteria, and/or fungus, preferably Escherichia coli, Staphylococcus aureus, and/or Candida albicans (claimed); for treating or preventing a bacterial or fungal infection in an organism; in cleaning and treatment solutions including disinfectants, detergents, household cleaner and washing powder formulations for applying to windows, floors, clothes, kitchen and restroom surfaces and surfaces in the area of food preparation and personal hygiene; as antibacterial ingredients in personal hygiene articles including soaps, shampoos, shower gels, ointments, creams, lotions, deodorants and disinfectants and storage solutions for contact lenses; toiletries including oral hygiene products to promote oral hygiene, and cosmetics including foundation make-up, eye liner, lip stick, and lip gloss; as mouth wash composition e.g. toothpaste or dentifrice composition; and in industrial settings including ship hulls, paper manufacturing, oil recovery and food processing. The ability of the hybrid nanomaterial (comprised of graphene oxide and quaternized chitosan) to inhibit the growth of microorganism was tested using biological assays. The results showed that hybrid nanomaterial inhibited the growth of Escherichia coli by 93.6 plus minus 4.2%. ADVANTAGE - The hybrid nanomaterial: possesses a synergistic effect, where antimicrobial efficacy of the hybrid nanomaterial is superior to its constituent components of graphene oxide and quaternized chitosan; exhibits good biocompatibility properties and reduced hemolytic activity; and is reusable. DETAILED DESCRIPTION - Hybrid nanomaterial comprises graphene oxide nanomaterial covalently conjugated to cationic quaternized chitosan, where the cationic quaternized chitosan is of formula (I). X1 = -NH-C(O)-CH3, -N(R1)(R2) or -N+(R3)(R4)(R5); R1-R5 = H or 1-18C alkyl; and k = 3-3000. Provided that at least one X1 is -N+(R3)(R4)(R5). INDEPENDENT CLAIMS are also included for: (1) preparing the hybrid nanomaterial, comprising reacting the cationic quaternized chitosan (I) with graphene oxide in the presence of a coupling reagent to covalently bond the cationic quaternized chitosan to the graphene oxide; and (2) an antimicrobial composition comprising the hybrid nanomaterial.