Thiourea‐Modified Multiwalled Carbon Nanotubes as Electrochemical Biosensor for Ultra‐Precise Detection of Dopamine

Abstract Functionalized multi‐walled carbon nanotubes (MWCNTs) have enticed remarkable attention in the field of electrochemical sensing applications. Dopamine (DA) is a monoamine neurotransmitter released in the brain acting as a chemical messenger that communicates messages between nerve cells and rest of the body. Therefore, there is a significant technological urge for the development of electrochemical sensors for DA in body fluids. In this context, nitrogen‐functionalized MWCNTs (TM‐CNT600) were fabricated by thermal annealing of carboxylic acid functionalized MWCNTs with thiourea at 600 °C under N₂ atmosphere. The XPS spectrum reveals the presence of nitrogen‐containing functionalities in the as‐prepared TM‐CNT600. FTIR results show the presence of −OH, C−N and C−S functional groups. XPS further corroborates the FTIR results and quantifies the predominant functional groups in as‐prepared material. The material was investigated as a potential electrochemical sensor for the detection of dopamine (DA). In the case of TM‐CNT600/GCE, a linear relationship for DA concentration was observed in the range of 10.7–24.2 μM with the limit of detection (LOD) of 1.42 μM using linear sweep voltammetry (LSV). These results highlight the potential of TM‐CNT600 modified GCE as an efficient sensor for the electrochemical detection of DA in body fluids.