Study On The Design Of Graphene-based Functional Mateirals And Electrochemical Sensing Properties

As the constant improvement of society, people’s life is getting better and better. However,many problems like environment pollution, food safety and health illnesses obstruct furtherdevelopment of society and threaten people’s security of lives and wealth. Electrochemialsensors could predict and monitor potential problems timely in various fields as a fast,portable and accurate sensor in result that all risks could be prevented as much as possible.Meanwhile, graphene exhibit promising application potential in electrochemical sensors as anovel material with excellent physical and chemical characteristics. In this paper, we focus onthe design of graphene-based functional materials and extend its application inelectrochemical sensors in order to improve the sensing properties of sensors.For the first part of this paper, two dimensional graphene prepared by reduction of graphiteoxide combined with Ag nanorods with ethylene glycol as reducing agent and solvent.Because of the combination of the high specific surface area and fast electron transport ratesof graphene with the high electrochemical catalytic activity of Ag nanomaterials, the resultinghybrids exhibit better performance for the non-enzymatic detection of hydrogen peroxide incomparison with pure Ag nanorods, with a linear detection range of0.1to70mM, and adetection limit of2.04mM at a signal-to noise ratio of3resulting in enhancing theelectrochemical sensing properties.For the second part of this paper, because of the self-aggregation of graphene sheets duringthe reduction of graphite oxide due to Van der vaals force and π-π interactions, the sensingproperties of electrochemical sensors are limited which can be found in last work andliteratures. Therefore, three dimensional graphene (3D-rGO) with open pore structure was prepared through a template-assisted self-assembly method. The product thus obtained exhibitgood sensing performances for electrochemical detection of dopamine (DA), leading to ahigh-performance DA sensor. The DA sensor based on3D-rGO materials has been evidencedto exhibit a better sensing performance than that of rGO and PVP-stabilizing rGO.Furthermore, the3D-rGO-based DA sensor could be effectively used for DA sensing in thepresence of ascorbic acid (AA) and uricacid (UA), indicating high selectivity of the DAsensor based on3D-rGO materials.For the last part of this paper, Polypyrrole (PPy) was combined with3D-rGO material forthe application in poisonous hydroquinone (HQ) electrochemical sensor. The resulting hybrid(3D-rGO/PPy) was evidenced to exhibt better electrochemical sensing properties thanrGO/PPy. Furthermore, the3D-rGO/PPy-based HQ sensor could be effectively used for HQsensing in the presence of Catechol (CC).