SYNTHESIS OF A HIGHLY EFFECTIVE rGO/Au NPs NANOCOMPOSITE FOR ADVANCED ELECTROCHEMICAL SENSOR APPLICATION
Iva Dimitrievska, Perica Paunovic, Anita Grozdanov
University Ss. Cyril and Methodius in Skopje, Faculty of Technology and Metallurgy, 1000 Skopje,
Rugjer Boshkovikj 16, North Macedonia
Researchers continuously work towards improving the surface kinetics of electrodes to design electrochemical sensors with advanced performance and satisfactory results in the field of therapeutic or diagnostic agents (drugs, genes, antibodies, biosensors, etc.) detection. Extensive research has been focused on screen-printed electrode (SPE) based sensors as electrochemical sensors for drug determination, particularly suitable for surface modification. Electrochemical sensors have been reported as one of the most favorable and practical methods for detection of pharmaceutical compounds in human samples, offering unique advantages such as miniaturization, portability, rapid response and satisfactory selectivity and sensitivity. Implementing nanotechnology to conventional electrochemical sensors results in better sensing mechanisms due to nanomaterials’ superior properties. Electrochemical sensors based on nanomaterials show incredible performance due to their large specific surface area and high reactivity, making them a highly popular topic among researchers. Carbon nanomaterials (graphene, carbon nanotubes, carbon nanorods, carbon nanoflakes, etc.) are the most widely used nanostructures as electrode modifiers and an excellent choice for electrochemical sensor performance improvement. Graphene is suitable for electrochemical sensing applications because of its nanoscale dimensions, and improvement of the overall sensitivity when increasing the number of surface electroactive centers and enhancing the rate of electron transfer. Gold nanoparticles find application in detection due to the unique combination of chemical and physical properties they possess, enabling the detection of biological molecules at low concentrations. Additionally, gold is frequently used in electrochemistry due to its high chemical inertness, as well as the high sensitivity resulting from reduced steric hindrance and improved electron exchange.
In our study, we propose a straightforward synthesis procedure for a novel nanocomposite aimed at developing sensitive electrochemical sensors capable of quantifying various pharmaceutical and biologically active compounds. The synthesized nanocomposite is based on reduced graphene oxide (rGO) decorated with gold nanoparticles (Au NPs) in three different concentrations (0.5, 2 and 4% wt.). The synthesis procedure was done in two phases: first - reduction of graphene oxide, using sodium borohydride (NaBH4) as a reducing agent, and second, decoration of the rGO with Au NPs using a gold colloidal solution. The rGO/Au NPs nanocomposites were obtained after a drying process at 40 °C in an oven. The characterization of the synthesized nanocomposite systems was done using Fourier-transform infrared spectroscopy (FTIR) and RAMAN, as primary identification techniques, along with scanning electron microscopy (SEM) as a powerful visual technique used to obtain detailed information about the particles’ morphology.
Keywords: nanocomposite, reduced graphene oxide, gold nanoparticles
Replies