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

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 coreactant. 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.

Advanced carbon nanomaterials for electrochemiluminescent biosensor applications

“…Graphitic carbon nitride finds applications as an alternative luminophore to the conventional ruthenium(II)tris(2,2'bipyridyl). The ECL of g-C3N4 is commonly generated by "reductive-oxidation" coreactant mechanism with peroxydisulfate, for a range of wavelength emission from 350 to 650 nm (Figure 4A) [52], furthermore tri-ethanolamine has been proposed for the "oxidative-reduction" coreactant mechanism [52,53].…”

“…Detection target analytes of biosensor using g-C3N4 are carcinoembryonic antigen [54 • ], proteins and enzymes (acetylcholinesterase and concanavalin A) [57,58], metal ions (Ni 2+ , Cd 2+ , Cu 2+ ) [52], small organic molecules, such as diclofenac [55], 17β-estradiol [59], dopamine [60], 8-Hydroxy-2'-deoxyguanosine [61], and Escherichia coli [62].…”

Host–Guest Recognition on 2D Graphitic Carbon Nitride for Nanosensing

“…Sui et al fabricated a PEC biosensor using g-C 3 N 4 nanosheets as a photoactive material coupled with a capture-release strategy. [132] DNA as Au NPs [133][134][135][136] and nanoflowers [137] and Ag NPs [138] modified with g-C 3 N 4 nanosheets, have been widely studied. Jiang et al developed a ratiometric ECL biosensor for the sensitive determination of glucose ( Figure 10a) using graphitic carbon nitride (Figure 10e)-supported Au nanocomposites (Au-g-C 3 N 4 ) ( Figure 10f) and luminol as the cathodic and anodic ECL emitters, respectively.…”

Graphitic-phase carbon nitride-based electrochemiluminescence sensing analyses: recent advances and perspectives

“…Zhu and coworkers developed a feasible label-free ECL aptasensor to detect acetylcholinesterase (AChE) in combination of Au NPs decorated g-C 3 N 4 and TEA as luminophore and anodic coreactant, respectively. 66 Since ECL systems are generally involved in four crucial reaction steps (i.e. redox reactions on electrode surface, homogeneous chemical reactions, the generation of excited state species, and light emission), 67 the ECL readouts can be regulated effectively by altering (accelerating or inhibiting) the above ECL pathways.…”