▎ 摘　　要

NOVELTY - Composition comprises (a) a graphene oxide nanoparticles (CNP) comprising several graphene sheets having several carboxylic acid groups and hydroxyl groups and inter-convertible open and closed forms, or (b) a water-soluble CNP having an encapsulated molecule, where the CNP comprising several graphene sheets having several carboxylic acid groups and hydroxyl groups and inter-convertible open and closed forms, where the open form has a size of 40-200 nm in breadth and length in open sheet form, the closed form has a diameter of 50-80 nm, the closed form is converted to the open form at a pH of 6.8 or lower, and the open form is converted to the closed form at a pH of 7 or greater. USE - The composition is useful for treating subject with cancer. The cancer is breast, ovarian, lung, bladder, prostate, melanoma, esophageal, stomach, other solid tumor cancers, or its combinations. The subject has glioblastoma (all claimed). ADVANTAGE - The composition ensures targeted delivery of therapeutics with enhanced bioavailability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: a method for performing reversible encapsulation of a molecule within the CNP involves (a) contacting the open form CNP with a molecule to-be-encapsulated, (b) converting the open form CNP to the closed form CNP with the encapsulated molecule by adjusting the pH to 7 or greater, and (c) releasing the encapsulated molecule from the closed form CNP by converting back to the open form CNP at a pH of 6.8 or lower; a method for treating a subject with cancer involves delivering a pH-sensitive water-soluble CNP having encapsulated molecule to the subject, where the encapsulated molecule is released from the CNP at a pH of 6.8 or lower after delivery to the subject; and a method for producing a pH-sensitive water-soluble CNP involves treating a material comprising one or a combination of wood, charcoal, low grade coal, or carbonized plant biomass with a dilute acidic solution to form a mixture of components including insoluble material and a second solution, separating the second solution from the insoluble material, neutralizing the second solution to form a precipitate, and separating the precipitate from the neutralized second solution, where the precipitate comprises the CNP.