An electrochemiluminescence aptasensor based on poly(aniline-luminol)/graphene oxide/chitosan for ultra-sensitive detection of Hg2+

It is of great significance for human health and environmental monitoring to establish an ultrasensitive assay method for Hg 2+ . In this work, a label-free and highly sensitive electrochemiluminescence (ECL) aptasensor was developed for the sensitive and selective detection of Hg 2+ without additional coreactants. Poly (aniline-luminol)/graphene oxide (P(ANi-Lu)/GO) nanocomposites were prepared, and chitosan (CS) was used to modify the surface of the material positively charged. The prepared P(ANi-Lu)/GO/CS was characterized by scanning electron microscopy (TEM), UV–Vis absorption spectra, fluorescence spectra and electrochemical impedance spectroscopy. The P(ANi-Lu)/GO/CS exhibited a stable and excellent electrochemiluminescence (ECL) property. Aptamer was adsorbed on P(ANi-Lu)/GO/CS sensing interface through electrostatic interaction, and Hg 2+ was detected using T-Hg 2+ -T configuration as ECL intensity controller. The results showed that Hg 2+ can be quantitatively determined in the range of 1.0 × 10 −15 ~1.0 × 10 −7  M with a detection limit of 4.8 × 10 −16  M. Graphical abstract