Real Time Detection of Hazardous Hydroxyl Radical Using an Electrochemical Approach

Abstract The proposed work demonstrates an electrochemical strategy for hydroxyl radical (•OH) detection based on aptamer immobilized glassy carbon electrode (GCE). To enhance the sensitivity of the detection method, nitrogen doped porous carbon nanostructures (N−C) and gold nanoparticles (AuNPs) were used as signal amplifiers. During biosensor fabrication, thiolated DNA and 6‐mercaptohexanol (MCH) were self assembled on N−C/AuNPs modified GCE surface. The fabricated biosensor was characterized electrochemically by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) which justified its high electronic conductivity. The aptamer immobilized electrode (N−C/AuNPs/DNA/MCH/GCE) was immersed in Fenton's reagent where oxidative damage of DNA occurred due to generated •OH. The DNA damage was monitored by hexaammineruthenium(III) (Ru(NH 3 ) 6 3+ ) which acted as electrochemical probe for sensitive detection of •OH. Square wave voltammetry (SWV) was used for •OH biosensing using simple, sensitive and rapid strategy at the fabricated electrode.