Halide perovskite materials have emerged as a new class of revolutionary photovoltaic and optoelectronic nanomaterials. However, the study on electrochemiluminescence (ECL) from halide perovskite nanomaterials is still in its infancy due to their instability, sensitivity, and difficulties in purification and film formation. Here, we propose a scraping coating method for the fabrication of high-quality halide perovskite quantum dot (QD) film on electrode, which shows dense and uniform packing with minimum grain size. When CsPbBr QDs are taken as model materials, highly efficient ECL can be obtained from such perovskite QD film with anhydrous ethyl acetate as both electrolyte and coreactant. The CsPbBr QD film displays intense and stable ECL with ultranarrow emission spectrum bandwidth (24 nm). The CsPbBr QD film shows an extremely high ECL efficiency which is up to 5 times relative to the standard Ru(bpy)/tri-n-propylamine system. This approach is universal and also applies to hybrid organic-inorganic halide perovskite QDs. This work not only extends the properties and applications of halide perovskite materials but also provides a new method for the in-depth study on the structure and properties of these kinds of materials.

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.