Ultra-fast synthesis of iron decorated multiwalled carbon nanotube composite materials: A sensitive electrochemical sensor for determining dopamine

Real-time monitoring of dopamine (DA) levels, a critical neurotransmitter involved in motor function and blood pressure regulation, requires more sensitive and selective sensors over a dynamic concentration range. The immense need to build highly efficient catalysts has always been at the forefront of electrochemical detection research toward DA. Herein, we design and synthesis an iron carbides-based heterostructure composite (Fe/Fe3C@CNT) by the introduction of microwave-assisted method and multiwalled carbon nanotubes (CNTs). Remarkably, it took only about 1.5 min to completely the preparation process including the pyrolysis of ferrocene (iron sources) and the formation of Fe/Fe3C nanoparticles uniformly distributed on the CNTs. Due to the unique heterostructure, enhanced electrical conductivity and adequate dispersion of active sites, the fabricated sensors exhibit favorable selectivity and great sensing property, yielding a distinguishable and selective response to DA down to 15 nM with a good linearity scope of 0.050–40 μM. The developed Fe/Fe3C@CNT electrode was then successfully applied to monitor the DA level from the real samples, which holds considerable promise for electrochemical detection and biosensing applications. •The Fe/Fe3C nanoparticles uniformly attached on the CNTs by a fast microwave-assisted method.•The particular heterostructure can provide rich active sites and achieve efficient catalytic performance.•The Fe/Fe3C@CNT/GCE exhibits great electrochemical sensing toward dopamine because of effective exposure of active sites.•The novel electrochemical sensor has the potential to detect dopamine in real biological serum samples.