Simultaneous Determination of Epinephrine, Acetaminophen and Tryptophan Using Pt-nanoparticles/Poly 4-(2,4- dihydroxyphenyl) Azohydroxylbenzene Film Modified Glassy Carbon Electrode

In recent years, electrochemically conductive polymers have been widely used owing to their excellent unique physical and chemical properties [1-2]. These electrodes show broad potential windows and can catalyze some electrochemical reaction which have high over potential andpoor selectivity [3]. Incorporation of nanoparticles with conductive polymers can be extensively enhancing the catalytic activity of electrode towards many biological molecules. Amongnanoparticles, platinum nanoparticles is one of the most stable nanoparticles which receive considerable attention because owing excellent electronic properties and biocompatibility. Acetaminophen is a widely-used analgesic and antipyretic drug, which is considered safe attherapeutic levels for humans with normal drug use. Overdoses of acetaminophen produce toxicmetabolite accumulation in liver, which may cause severe and sometimes fatal hepatoxicity and nephrotoxicity. The stimulatory effect of acetaminophen on cyclo-oxygenase activity in intactcells was abolished in the presence of electron-donating co-factor epinephrine [5]. Acetaminophen administration also is known to increase brain neurotransmitter serotonin levels because Acetaminophen alters tryptophane metabolism by inhibiting tryptophan 2,3-dioxygenase. Therefore, simultaneous determination of epinephrine, acetaminophen and tryptophane is important. In this study, Pt nanoparticles supported on glassy carbon electrode (GCE) by simple electrodeposition technique. In this study a novel platinum nanoparticles poly 4-(2,4-dihydroxyphenyl) azo-hydroxyl benzene (DAHB) film modified glassy carbon electrode was fabricated for the simultaneous determination of epinephrine, acetaminophen and tryptophane. The bare glassy carbon electrode (GCE) fails to separate the oxidation peak potentials of these molecules while poly-DAHB film modified GCE can resolve them. Electrochemical impedance spectroscopy (EIS) study indicates that charge transfer resistance of bare electrode increased as poly-DAHB was electropolymerized at the bare electrode. Furthermore, EIS exhibit enhancementof electron transfer kinetics between analytes and electrode after electrodeposition of Pt nanoparticles. Differential pulse voltammetry results show that the electrocatalytic current increase linearly in the ranges of 2-540 μmol L–1 for epinephrine, 5-820 μmol L–1 foracetaminophen and 1.0-560 μmol L–1 for tryptophan with detection limits (S/N =3) of 0.1 μmol L-1, 0.04 μmol L-1 and 0.2 μmol L-1 for epinephrine, acetaminophen and tryptophan.

کلیدواژه ها:

Simultaneous determination ، Epinephrine ، Acetaminophen ، Tryptophan ، Poly 4-(2 ، 4-dihydroxyphenyl) azo-hydroxyl benzene modified GC electrode ، Pt nanoparticles