▎ 摘　　要

NOVELTY - A nitrogen-doped graphene composite horseradish peroxidase-based hydroquinone biosensor comprises a reference electrode, a counter electrode and a modified working electrode. The modified working electrode is composed of a base electrode, and a substance recognition film solidified on the surface of the base electrode. The substance recognition film is mainly prepared by mixing nitrogen-doped graphene dispersion, horseradish peroxidase solution and chitosan solution. The nitrogen-doped graphene dispersion is obtained by dispersing nitrogen-doped graphene in water. The horseradish peroxidase solution is obtained by dissolving horseradish peroxidase in a phosphate-buffered saline solution. The chitosan solution is obtained by formulating chitosan into a solution. The mass ratio of nitrogen-doped graphene, horseradish peroxidase and chitosan is (2-20):(15-35):10. USE - The nitrogen-doped graphene composite horseradish peroxidase-based hydroquinone biosensor is useful for detecting hydroquinone (claimed). ADVANTAGE - The nitrogen-doped graphene composite horseradish peroxidase-based hydroquinone biosensor: is prepared by a simple method in an economical manner; has wide detection range, a low detection limit, high selectivity, sensitivity and stability, and excellent electrocatalytic performance; and accurately detects hydroquinone. DETAILED DESCRIPTION - A nitrogen-doped graphene composite horseradish peroxidase-based hydroquinone biosensor comprises a reference electrode, a counter electrode and a modified working electrode. The modified working electrode is composed of a base electrode, and a substance recognition film solidified on the surface of the base electrode. The substance recognition film is mainly prepared by mixing nitrogen-doped graphene dispersion, horseradish peroxidase solution and chitosan solution. The nitrogen-doped graphene dispersion is obtained by dispersing nitrogen-doped graphene in water. The horseradish peroxidase solution is obtained by dissolving horseradish peroxidase in a phosphate-buffered saline solution. The chitosan solution is obtained by formulating chitosan into a solution. The mass ratio of nitrogen-doped graphene, horseradish peroxidase and chitosan is (2-20):(15-35):10. The nitrogen-doped graphene is specifically prepared: (a) uniformly dispersing graphene oxide and aniline, polymerizing aniline in an acidic medium under the action of an oxidizing agent and placing in a hydrothermal reaction vessel for hydrothermal reaction to obtain a polyaniline-graphene oxide composite; and (b) calcining the polyaniline-graphene oxide composite at 400-500 degrees C and then continuously calcining 700-800 degrees C.