Ethyl 2-Cyanoacrylate as a Promising Matrix for Carbon Nanomaterial-Based Amperometric Sensors for Neurotransmitter Monitoring

Dopamine (DA) is a critical catecholaminergic neurotransmitter that facilitates signal transduction across synaptic junctions and modulates essential neurophysiological pro cesses, including motor coordination, motivational drive, and reward-motivated behav iors. The fabrication of cost-effective, miniaturized, and high-fidelity analytical platforms is imperative for real-time DA monitoring. Due to its inherent electrochemical activity, carbon-based amperometric sensors constitute the primary modality for DA quantifica tion. In this study, graphite, multi-walled carbon nanotubes (MWCNTs), and graphene were immobilized within an ethyl 2-cyanoacrylate (ECA) polymer matrix. ECA was se lected for its rapid polymerization kinetics and established biocompatibility in electro chemical frameworks. All fabricated composites demonstrated robust electrocatalytic ac tivity toward DA; however, MWCNT- and graphene-based sensors exhibited superior an alytical performance, characterized by highly competitive limits of detection (LOD) and quantification (LOQ). Specifically, MWCNT-modified electrodes achieved an interesting LOD of 0.030 ± 0.001 µM and an LOQ of 0.101 ± 0.008 µM. Discrepancies in baseline cur rent amplitudes suggest that the spatial orientation of carbonaceous nanomaterials within the cyanoacrylate matrix significantly influences the electrochemical surface area and re sulting baseline characteristics. The impact of interfering species commonly found in bio logical environments on the sensors’ response was systematically evaluated. The best performing sensor, the graphene-based one, was used to measure the DA intracellular content of PC12 cells.