Facile Synthesis of Graphene/Cobalt Oxide Nanohexagons for the Selective Detection of Dopamine

Abstract

1Introduction Dopamine (4-(2-aminoethyl) benzene-1,2d iol) is ac atecholamine derivative,s ecreted naturally in the mid brain region of mammals [1].A saneurotransmitter, dopamine (DA) distributioni nther ange of 10 À6 to 10 À8 Ma ts ubstantia nigra( mid brain region)i sr esponsible for the humanm etabolism [1a, 2].I tc ontrols simultaneously the functioning of both central nervous system and renal system [3].A lthough DA has an umber of inevitable roles,its abnormals ecretioninhuman beings leads to various disorders relatedw ith human brain. And so,t he determination of DA level is highly important for diagnosing diseases namely Parkinsons, Alzheimers, epilepsy, pheochromocytoma and so on [4].N umber of methods including electrochemical [1b],c hromatography [5],s pectrophotometry [6] and colorimetry [7] therefore have been used for the determination of DA.P articularly,e lectrochemical method is preferred for the determinationo f DA in recent years on account of its simplicity,s hort working time,l ow cost and high sensitivity compared to other methods [8].H owever, electrode fouling, large over potential and selectivity are the main key issues to ignore the unmodified electrode in the fabricationo fd opamine sensor. To minimize these key issues,n umbero fmetal and metal oxides supported along with carbon materials have been used to modify the electrodes urface in recent years [9].Cobalt oxide (Co 3 O 4 )h as proved to be ap romisingi norganicm etal oxide for the electrodef abrication in numerousa pplications such as super capacitors [10],l ithium ion batteries[ 11],s odium-ion batteries [12] and biosensors [13] ascribed to its low cost, structural flexibility, high theoretical specificc apacitance, great redoxa ctivity, durability and good catalytic activity.C o 3 O 4 is aP -type semiconductor with directb and gap of 1.5 eV and 2.19 eV [14].B ased on its structural feasibility,s everal nano structures includingr ods [15],t ubes [16],w ires [17],r ing [18], bubbles [19] etc. have been prepared throughv arious methods. However, simple and ecofriendly approaches are highly desirable for the synthesis of nanomaterials [20].H erein, we have prepared Co 3 O 4 nanohexagons using ab iomolecule ascorbic acid as reducing and capping agent. Recently,C o 3 O 4 and its compositesh ave been prepareda nd used for the fabrication of sensors and biosensors [21].M ost of the fabricated Co 3 O 4 based nanocomposite sensors are used for the determination of biomolecules like glucose and hydrogenp eroxide [13,22].T o increase the sensitivity of fabricated Co 3 O 4 modified glassy carbon electrode,r esearchers have focused on the preparation and fabrication of graphene based Co 3 O 4 sensors [21,23].H igh surface area, good conductivity are the main advantages for choosing graphene as as upporting mat relative to other carbon materials such as carbon Abstract:T his work presents as imple green approachf or the chemicals ynthesis of cobalt oxide nano hexagons (Co 3 O 4 NHs) with an average size of 160 AE 40 nm incorporatedg raphene na...

Co/Co‐N@Nanoporous Carbon Derived from ZIF‐67: A Highly Sensitive and Selective Electrochemical Dopamine Sensor

“…Here, the use of carbon materials is highly desired, as they provide enhanced electrical conductivity, large specific surface area, and chemical stability . Recently, cobalt based nanostructures like graphene/cobalt oxide and multi‐walled carbon nanotube/cobalt nanoparticles were identified for the selective detection of dopamine . These cobalt based materials possess advantages including low cost and high electrochemical stability .…”

Microelectrode Arrays Modified with Nafion/Nanoporous AuPt Nanoparticles for in vivo Detection of Dopamine

“…(12)(13)(14) Another important factor for developing in vivo DA electrochemical sensors is the sensitivity. Because the sensitivity of an electrochemical sensor is directly related to the electrode surface area and conductivity, a variety of nanostructured materials, such as metal oxide nanoparticles, (15)(16)(17) carbon nanotubes, (18,19) metal or bimetallic nanoparticles, (20)(21)(22)(23) graphene, (24)(25)(26) and nanocomposites, (27,28) have been proposed to modify the electrode.…”