SINCE RELIABLE AND FAST DETERMINATION OF H2O2 IS IMPORTANT IN MANY AREAS SUCH AS MEDICINE, FOOD CONTROL, ENVIRONMENTAL PROTECTION, AND A KEY FACTOR IN THE DEVELOPMENT OF EFFICIENT BIOSENSORS, THE STUDY OF ELECTROCHEMICAL H2O2 SENSOR HAS ATTRACTED EXTENSIVE ATTENTION [1].HOWEVER, THERE ARE SEVERAL DISADVANTAGES OF THE ENZYME-MODIFIED ELECTRODES, SUCH AS INSTABILITY, HIGH COST OF ENZYMES AND COMPLICATED IMMOBILIZATION PROCEDURE. THE ACTIVITY OF ENZYMES CAN BE EASILY AFFECTED BY TEMPERATURE, PH VALUE, AND TOXIC CHEMICALS. IN ORDER TO SOLVE THESE PROBLEMS, CONSIDERABLE ATTENTION HAS BEEN PAID TO DEVELOP NONENZYMATIC ELECTRODES, FOR INSTANCE, NOBLE METALS, METAL ALLOYS, AND METAL NANOPARTICLES [2].RECENTLY, GRAPHENENANOSHEETS (GNS) HAVE AROUSED EXTENSIVE INTERESTS IN ELECTROCHEMISTRY FILED DUE TO ITS HIGH SURFACE AREA, SUPER CONDUCTIVITY AND WIDE POTENTIAL WINDOW [3].IN PRESENT WORK, THE GRAPHENE/NILE BLUE NANOCOMPOSITEELECTRODE WAS PREPARED BY SPRAYING 10MLGRAPHENE OXIDE/NILE BLUE (GO/NB) HOMOGENEOUS SOLUTION ONTO GC (0.03 CM2) DISK SURFACE AND DRIED. THEN, THE OBTAINED GO/NB-GC ELECTRODE WAS SCANNED 14 CYCLES IN KNO3 N2-SATURATED SOLUTION FROM 0.0 TO-1.3 V AT 20 MV S-1 AND THE RESULTING ELECTRODE WAS DENOTED AS ERGO/ NB-GC. FOR COMPARISON, THE ER-GO/GC ELECTRODE WAS ALSO SYNTHESIZED BY THE SAME WAY. THE CATALYTIC PERFORMANCE OF THIS SENSOR FOR H2O2 REDUCTIONIS INVESTIGATED USING A CYCLIC VOLTAMMETRY (CV) IN PBS (PH=7) IN THE ABSENCE OR PRESENCE OF H2O2.THESE RESULTS INDICATED THAT THE MODIFICATION OF NB ON THE SURFACE OF GO SHEETS SIGNIFICANTLY IMPROVED THE ELECTROCATALYTICACTIVITY TOWARDS THE REDUCTION OF H2O2. THEREFORE, THE CATALYTIC NATURE OF NB COMBINED WITH THE HIGH SURFACE AREA OF GNSTOWARDS H2O2MAKES HOLD THE PROMISE FOR THE DEVELOPMENT OF NONENZYMATIC SENSOR AT LOW COST.

FOR DIAGNOSIS AND MANAGEMENT OF DIABETES, PRECISE AND ACCURATE DETECTION OF GLUCOSE IS VERY IMPORTANT. THEREFORE, PRODUCING HIGH-PERFORMANCE ANALYTICAL TOOLS FOR DIAGNOSIS OF DIABETES AND MANAGEMENT OF BLOOD GLUCOSE IS VERY CRUCIAL. GLUCOSE OXIDASE BASED BIOSENSORS HAVE BEEN PROVED TO BE POWERFUL DEVICES FOR GLUCOSE DETERMINATION THANKS TO THEIR HIGH SELECTIVITY, SENSITIVITY AND LOW DETECTION LIMIT. HOWEVER, THESE BIOSENSORS DUE TO THE INTRINSIC FEATURE OF ENZYMES HAVE SOME DEFECTS IN STABILITY AND REPRODUCIBILITY. THEREFORE, THE NON-ENZYMATIC GLUCOSE BIOSENSORS BASED ON METAL NANOPARTICLES AND METAL OXIDES HAVE RECEIVED MORE AND MORE ATTENTIONS. NON-ENZYMATIC BIOSENSORS HAVE MANY ADVANTAGES SUCH AS SIMPLE PREPARATION, LOW COST, HIGH STABILITY AND SENSITIVITY. IN CURRENT STUDY, WE COMBINED CUO NANOPARTICLES WITH PALLADIUM AND CARBON NANOTUBES TO PRODUCE A NANOCOMPOSITE (CUO-PALLADIUM/CNT) FOR NONENZYMATIC DETECTION OF BLOOD GLUCOSE. BASED ON CYCLIC VOLTAMMETRIC RESULTS CUOPALLADIUM/ CNT NANOCOMPOSITE HAS A HIGH SENSITIVITY (2000 MA MM-1 CM-2), GOOD LINEAR RANGE (0.002-7 MM), LOW DETECTION LIMIT (0.2 MM) AND SHORT RESPONSE TIME, GOOD ANTI-INTERFERENCE AND ANTI-TOXICITY, LONG-TERM STABILITY (OVER 8 WEEKS). NON-ENZYMATIC GLUCOSE BIOSENSORS LIKE CUOPALLADIUM/ CNT NANOCOMPOSITE ALLEVIATED THE PROBLEMS OF ENZYME-BASED BIOSENSORS SUCH AS INSUFFICIENT STABILITY, SENSITIVITY TO TEMPERATURE, PH AND HUMIDITY, LOWER REPRODUCIBILITY, THERMAL AND CHEMICAL INSTABILITY. BECAUSE OF THESE PROPERTIES AND EASY PREPARATION METHOD, CUOPALLADIUM/ CNT NANOCOMPOSITE IS A PROMISING MATERIAL FOR MARKETING OF GLUCOSE BIOSENSORS.ALSO COMPLEMENTARY EXPERIMENTS TO EXAMINE THE SENSOR FOR DETECTION OF GLUCOSE IN REAL HUMAN SERUM ARE CONSIDERED.

XANTHINE (3, 7-DIHYDRO-PURINE-2, 6-DIONE) IS THE DEGRADATION PRODUCT OF GUANINE AND HYPOXANTHINE AND IS PREVALENT IN MOST BODY TISSUES, BLOOD, AND URINE. UNTIL NOW, XANTHINE DETECTION METHODS HAVE INVOLVED MAINLY ELECTRO-CHEMICAL BIOSENSORS BASED ON IMMOBILIZED...