RECENTLY, IT WAS FOUND THAT A GROUP OF ORGANIC MOLECULES HAVING SIMILAR STRUCTURES CAN BE SEPARATED FROM EACH OTHER ACCORDING TO THEIR ADSORPTION STRENGTHS ONTO THE SURFACES OF METAL OXIDES. IRON OXIDES AND IRON HYDROXIDES HAVE ABILITY TO ADSORB GLUCOSE IN AQUEOUS SOLUTION. IT SEEMS THAT GLUCOSE BINDS WITH MINERAL SURFACES CREATES HYDROGEN BONDING.ELECTROCATALYTIC OXIDATION OF GLUCOSE HAS A CRUCIAL ROLE IN MEASURING BLOOD SUGAR BY BLOOD GLUCOSE SENSORS. METAL ELECTRODES (CU, CO, CD, AU, AG, ETC.) CAN BE USED AS AN ELECTROCATALYST FOR OXIDATION OF GLUCOSE. AG ELECTRODES HAVE A HIGH SENSITIVITY IN GLUCOSE OXIDATION. THEREFORE, IT WAS SUGGESTED THAT THE MODIFIED AG ELECTRODES WITH METAL OXIDES MIGHT BE MORE SENSITIVE TO GLUCOSE THAN THE AG ELECTRODES.. IN THIS STUDY, IRON OXIDES (FE3O4, FE2O3) AND IRON HYDROXIDES (FEOOH) NANOPARTICLES, WERE FIRSTLY SYNTHESIZED AND THEN USED AS A SUBSTRATE FOR DEPOSITION OF SILVER NANOPARTICLES. THE SYNTHESIZED HETERODIMERIC NANOPARTICLES (FE3O4-AG, FE2O3-AG AND FEOOH-AG) WERE USED AS A MODIFIER MATERIAL IN PREPARATION OF THE MODIFIED CARBON PASTE ELECTRODES. THE PREPARED ELECTRODES SHOWED HIGH AFFINITY TOWARDS GLUCOSE. THE HETRODIMERIC NANOPARTICLES WERE PHYSICALLY CHARACTERIZED BY UV-VIS SPECTROPHOTOMETRY, SCANNING ELECTRON MICROSCOPY (SEM), TRANSMISSION ELECTRON MICROSCOPY (TEM) AND X-RAY DIFFRACTION (XRD) ANALYSIS. ELECTROCHEMICAL BEHAVIORS OF THE HETERODIMERIC NANOPARTICLES WERE INVESTIGATED BY CYCLIC VOLTAMMETRY. THE NONENZYMATIC OXIDATION PEAK OF GLUCOSE AND ITS INTERMEDIATES ON THE SURFACE OF ELECTRODES (VERSUS AG/AGCL) WERE OBSERVED IN ALKALINE SOLUTION. THE RESULTS SHOWED THAT THE SENSIVITY OF THE ELECTRODE BASED ON FE3O4-AG NANOPARTICLES WAS GREATER THAN THAT OF THE ELECTRODES BASED ON THE OTHER SYNTHESIZED HETERODIMERIC NANOPARTICLES. THE EFFECTS OF VARIOUS PARAMETERS SUCH AS CARBON PASTE COMPOSITION, TYPE OF ELECTROLYTE, PH AND SCAN RATE, ON THE RESPONSE OF THE PREPARED BIOSENSOR WERE STUDIED. UNDER THE OPTIMUM CONDITIONS, THE BIOSENSOR WAS APPLIED TO DETERMINE GLUCOSE IN HUMAN SERUM.

BACKGROUND: CATALYTIC ACTIVITIES OF NANOPARTICLES DIFFER FROM THE CHEMICAL PROPERTIES OF THE BULK MATERIALS. FOR INSTANCE SHOWED THAT THE BLEACHING OF THE ORGANIC DYES BY APPLICATION OF POTASSIUM PEROXODISULPHATE IN AQUEOUS SOLUTION AT ROOM TEMPERATURE IS ENHANCED STRONGLY BY THE APPLICATION OF SILVER CONTAINING NANOPARTICLES. FURTHERMORE, AGNPS WAS FOUND TO CATALYZE THE CHEMILUMINESCENCE FROM LUMINOL-HYDROGEN PEROXIDE SYSTEM WITH CATALYTIC ACTIVITY BETTER THAN AU AND PT COLLOID [1]. QUINOXALINES ARE IMPORTANT HETEROCYCLES IN MEDICINAL CHEMISTRY AND HAVE BIOLOGICAL ACTIVITIES SUCH AS ANTIBACTERIAL ACTIVITIES. THE BEST REPORTED METHOD FOR SYNTHESIS OF QUINOXALINES IS THE REACTION OF ARYL 1, 2-DIAMINES WITH A 1, 2-DICARBONYL COMPOUNDS IN THE PRESENCE CATALYSES NI-NANOPARTICLES [2], GALLIUM (III) TRIFLATE [3], TASK-SPECIFIC IONIC LIQUIDS [4], AND MNCL2 HAVE BEEN APPLIED IN THE ABOVE MENTIONED METHOD.METHODS: PREPRATION OF QUINOXALINES CATALYZED USING AG NANOPARTICLES: A MIXTURE OF O-PHENYLENEDIAMINE (1 MMOL), 1, 2-DICARBONYL (1 MMOL) AND CATALYST (0.03 GR) AG NANOPARTICLES WAS HEATED AT 50OC FOR 2-10 MINUTE. THE PROGRESS OF THE REACTION WAS MONITORED BY TLC. AFTER COMPLETION OF THE REACTION, THE MIXTURE WAS DISSOLVED IN CH2CL2, FILTERED AND WASHED WITH DIETHYLETHER (5ML) TO ISOLATE OF CATALYST. THE SOLVENT WAS EVAPORATED UNDER REDUCED PRESSURE AND THE PURE PRODUCT WAS OBTAINED.RESULTS: IN CONTINUATION OF OUR INVESTIGATIONS ON THE APPLICATIONS OF SOLID ACIDS IN ORGANIC SYNTHESIS, WE HAVE INVESTIGATED THE SYNTHESIS OF QUINOXALINES IN THE PRESENCE OF AG NANOPARTICLES AT ROOM TEMPERATURE. HEREIN, WE REPORT THAT AG NANOPARTICLES ARE EFFICIENT CATALYSTS FOR THE SYNTHESIS OF QUINOXALINE DERIVATIVES COMPARABLE WITH SOME OTHER APPLIED CATALYSTS. THE REACTION OF 1, 2-PHENYLENEDIAMINE WITH BENZIL WAS INVESTIGATED FOR OPTIMIZATION OF THE REACTION CONDITIONS. REACTION AT DIFFERENT TEMPERATURES, DIFFERENT SOLVENT AND VARIOUS MOLAR RATIOS OF SUBSTRATES IN THE PRESENCE OF AG NANOPARTICLES REVEALED THAT THE BEST RESULTS WERE OBTAINED UNDER SOLVENTFREE CONDITIONS AT ROOM TEMPERATURE AND A MOLAR RATIO OF 1, 2-PHENYLENEDIAMINE: BENZYL: 1:1 AND NANOPARTICLES (0.03 GR). VARIOUS 1, 2-PHENYLENEDIAMINES AND 1, 2-DIKETONES WERE USED AS SUBSTRATES FOR THE SYNTHESIS OF QUINOXALINES UNDER SOLVENT FREE AT ROOM TEMPERATURE (SCHEME 1).