Label‐Free Electrochemiluminescence Aptasensor for Highly Sensitive Detection of Acetylcholinesterase Based on Au‐Nanoparticle‐Functionalized g‐C₃N₄ Nanohybrid

Abstract

Abstract A feasible label‐free electrochemiluminescence (ECL) aptasensor that uses an Au‐nanoparticle‐functionalized g‐C 3 N 4 nanohybrid (Au‐g‐C 3 N 4 NH) as the luminophore was constructed for highly sensitive acetylcholinesterase (AChE) detection. The sensor was fabricated by successively modifying a glassy carbon electrode with Au‐g‐C 3 N 4 NH and thiol‐modified AChE‐specific aptamers. In the presence of AChE, the ECL signal decreased significantly, because AChE could hydrolyze the substrate acetylthiocholine to generate acetic acid, which could react with the co‐reactant triethylamine (Et 3 N), leading to evident consumption of the co‐reactant. The ECL response of the aptasensor was linearly proportional to the concentration of AChE ranging from 0.1 pg/mL to 10 ng/mL, with a detection limit of 42.3 fg/mL ( S / N =3). This novel ECL sensing strategy demonstrated a highly sensitive and selective method for AChE detection and was expected to possess potential applications in clinical diagnosis and biomedical technology.