An electrogenerated chemiluminescent biosensor based on a g-C3N4–hemin nanocomposite and hollow gold nanoparticles for the detection of lactate

Abstract

In this article, a new electrochemiluminescent (ECL) biosensor based on a g-C₃N₄–hemin nanocomposite and hollow gold nanoparticles (HGNPs) was constructed to detect lactate. Firstly, the g-C₃N₄ nanosheets were prepared through ultrasonication-assisted liquid exfoliation of bulk g-C₃N₄, which was obtained through polymerizing melamine under 600 °C. Then, the nanocomposites of g-C₃N₄ nanosheets and hemin were prepared to modify a glassy carbon electrode. Subsequently, HGNPs were self-assembled onto the electrode for adsorbing lactate oxidase to achieve a lactate biosensor. Due to the excellent catalytic effect of g-C₃N₄–hemin and HGNPs on the luminol/H₂O₂ ECL system, the as-prepared biosensor exhibited a good response performance to lactate with a linear range of 1.7 × 10⁻⁸ to 5.0 × 10⁻⁴ M and a detection limit of 5.5 × 10⁻⁹ M. In addition, the prepared ECL biosensor exhibited satisfying reproducibility and stability. The g-C₃N₄–hemin nanocomposite might have great potential application in a luminol/H₂O₂ ECL system.