Effect of heating power towards synthesis of carbon dots through microwave pyrolysis method for optical-based biosensor

Abstract

This study focuses on the effect of heating power in producing carbon dots (CDs) using microwave-assisted pyrolysis from glucose and PEG-200. Glucose is one type of saccharide that contains carbon atom in their structure while PEG-200 is a polymer that acts as a stabilizer. Synthesis of CDs was carried out by using a domestic microwave at different heating power ranging from 300 to 600 Watts. Produced CDs were subjected to dilution, filtering and dialysis procedure for purification purpose. UV-Vis was carried out using PerkinElmer Lambda 35 Spectrophotometer to prove the present of carbon dots in the sample solution. Photoluminescence intensity was observed using Horiba FluoroLog Spectrophotometer together with Horiba iHR550 Imaging Spectrometer to show the emission wavelength and the emission color of CDs prepared. UV-Vis results show the present of CDs in each sample from absorption peaks in the range between 240 nm until 260 nm. The photoluminescence testing shows the emission wavelength of prepared CDs solution is around 430 nm to 570 nm which represent emission color of green-yellow luminescence. From this experiment, CDs that were prepared using a heating power of 450 Watt in 2 minutes and went through the filtering process produce the best luminescence properties. Prepared CDs display electrochemiluminescence (ECL) properties in the presence of co-reactant potassium peroxydisulfate using cyclic voltammetry to pave the way for optical-based biosensor application.