In situ polymerization confinement synthesis of ultrasmall MoTe2 nanoparticles for the electrochemical detection of dopamine

Abstract

Transition metal dichalcogenides (TMDs) with unique electronic features have attracted tremendous attention in the catalysis and electrochemical sensing area. Decreasing the size and dimension from two-dimensional layered structures to zero-dimensional ultrasmall nanoparticles with quantum confinement and edge effects generates a larger specific surface area and plentiful active sites. However, the inherently layered structure challenges the synthesis of ultrasmall nanoparticles of MoTe₂. Herein, in situ polymerization confined Mo atoms have been first immobilized onto N-doped carbon, the reaction of which with Te results in the formation of ultrasmall MoTe₂ nanoparticles. The as-obtained N-doped carbon-supported molybdenum ditelluride (MoTe₂/NC) exhibited excellent sensitivity towards the electrochemical detection of dopamine ranging from 100 nM to 50 μM with a very low detection limit of 7.8 nM (S/N = 3). Simultaneously, it also possessed robust stability and selectivity toward detecting dopamine. This study offers a new strategy for the achievement of monodisperse ultrasmall MoTe₂ nanoparticles, which may be extended to the synthesis of other metal dichalcogenides for various applications in the fields of catalysis and sensing.