▎ 摘　　要

NOVELTY - An oxide-based graphene nitrogen-doped carbon dot surface printing fluorescent sensor is prepared by taking adding ammonium citrate, ethylenediamine and deionized water, carrying out hydrothermal reaction, cooling, filtering, taking filtrate, putting into 3500 Da dialysis bag, dialyzing, freeze drying, obtaining nitrogen-doped carbon dot (NCDs), dispersing graphene oxide in ethanol, adding 4-nitrophenol and methacrylic acid, adding NCDs ethanol solution, self-assembling, stirring overnight, water bath heating, and adding ethylene glycol dimethylacrylate and azobisisobutyronitrile. USE - Method for preparing oxide-based graphene nitrogen-doped carbon dot surface printing fluorescent sensor (claimed). ADVANTAGE - The sensor has good stability, and has fast and sensitive fluorescence detection. It is suitable for specific detection of 4-nitrophenol in complex sample, and monitoring and detection in environment and food. DETAILED DESCRIPTION - An oxide-based graphene nitrogen-doped carbon dot surface printing fluorescent sensor is prepared by taking adding ammonium citrate, ethylenediamine and deionized water, carrying out hydrothermal reaction, cooling, filtering, taking filtrate, putting into 3500 Da dialysis bag, dialyzing, freeze drying, obtaining nitrogen-doped carbon dot (NCDs), dispersing graphene oxide in ethanol, adding 4-nitrophenol (4-NP) and methacrylic acid, adding NCDs ethanol solution, self-assembling, stirring overnight, water bath heating, adding ethylene glycol dimethylacrylate and azobisisobutyronitrile, pumping nitrogen, carrying out polymerization reaction, washing product with ethanol, vacuum drying, carrying out Soxhlet extraction, washing with methanol/acetic acid mixed solution, eluting 4-NP template, and vacuum drying. An INDEPENDENT CLAIM is included for 4-nitrophenol detection method comprising taking 10 mL oxide-based graphene nitrogen-doped carbon dot surface printing fluorescent sensor solution, 0.1 mol/L hydrochloric acid or 0.1 mol/L ammonia aqueous solution, adjusting pH value to 7.0, mixing for 40 minutes to regulate concentration to 0-40 mu mol/L, and detecting emitting wavelength and fluorescence intensity.