Pore Confinement-Enhanced Electrochemiluminescence on SnO₂ Nanocrystal Xerogel with NO₃^– As Co-Reactant and Its Application in Facile and Sensitive Bioanalysis

Abstract

Herein, 10-fold electrochemiluminescence (ECL) enhancement from a porous SnO 2 nanocrystal (SnO 2 NC) xerogel (vs discrete SnO 2 NCs) was first observed with NO 3 − as a novel coreactant. This new booster phenomenon caused by pore characteristic was defined as "pore confinement-induced ECL enhancement", which originated from two possible reasons: First, the SnO 2 NC xerogel with hierarchically porous structure could not only localize massive luminophore near the electrode surface, more importantly, but could accelerate the electrochemical and chemiluminescence reaction efficiency because the pore channels of xerogel could promote the mass transport and electron transfer in the confined spaces. Second, the NO 3 − could be in situ reduced easily to the active nitrogen species by means of the pore confinement effect, which could be served as a new coreactant for nanocrystal-based ECL amplification with the excellent stability and good biocompatibility. As a proof of concept, a facile and sensitive sensing platform for SO 3 2− detection has been successfully constructed upon effectively quenching of SO 3 2− toward the SnO 2 NC xerogel/NO 3 − ECL system. The key feature about this work presented a grand avenue to achieve the strong ECL signal, especially from weak emitters, which gave a fresh impetus to the construction of new-generation of surface-confined ECL platform with potential applications in ECL imaging and sensing.

Iodine Capture with Mechanically Robust Heat-Treated Ag–Al–Si–O Xerogel Sorbents

“… 52 Lei et al synthesized SnO 2 nanocrystalline xerogels to enhance the electrochemiluminescence reaction and applied it to detect SO 3 2– . 50 …”

MicroRNA-Triggered Deconstruction of Field-Free Spherical Nucleic Acid as an Electrochemiluminescence Biosensing Switch

“…16,17 For example, Lei and colleagues reported a porous SnO 2 nanocrystal (SnO 2 NC) xerogel served as a confined space to promote the electron transfer of the active intermediates, resulting in a 10-fold ECL enhancement in comparison to the discrete SnO 2 NC. 18 Therefore, inspired by these findings, we proposed a collaborative strategy by the integration of a self-accelerated approach and pore confinement-enhanced ECL effect, loading the monodisperse rubrene (Rub) and Pt nanoparticles (PtNPs) into the mesoporous silica nanospheres (mSiO 2 NSs) for strong and stable ECL outputs (Scheme 1A).…”

“…To solve this problem, a self-accelerated ECL enhancement strategy of silver nanoparticle (AgNP)-functionalized SnO 2 nanoflowers (Ag@SnO 2 NFs) was proposed by the use of SnO 2 as emitters and AgNPs as coreaction accelerators to obtain strong and stable ECL emission in K 2 S 2 O 8 solution (S 2 O 8 2– as coreactants) . Recently, a new pore confinement-induced ECL enhancement has stimulated a strong interest and given a new impetus to improve the reaction efficiency of the ECL emitters. , For example, Lei and colleagues reported a porous SnO 2 nanocrystal (SnO 2 NC) xerogel served as a confined space to promote the electron transfer of the active intermediates, resulting in a 10-fold ECL enhancement in comparison to the discrete SnO 2 NC . Therefore, inspired by these findings, we proposed a collaborative strategy by the integration of a self-accelerated approach and pore confinement-enhanced ECL effect, loading the monodisperse rubrene (Rub) and Pt nanoparticles (PtNPs) into the mesoporous silica nanospheres (mSiO 2 NSs) for strong and stable ECL outputs (Scheme A).…”

In Situ Controllable Generation of Copper Nanoclusters Confined in a Poly-l-Cysteine Porous Film with Enhanced Electrochemiluminescence for Alkaline Phosphatase Detection

“…Recently, our group first prepared stannic oxide (SnO 2 ) nanocrystal xerogel with a porous structure, which enhanced the ECL by tenfold compared with that of discrete SnO 2 NCs. 20 Zeng and colleagues selected covalent organic frameworks with a porous structure as microreactors to assemble tris(2,2′-bipyridyl) ruthenium(II) (Ru(bpy) 3 2+ ), which realized the confinement-enhanced ECL. 21 However, the construction of these solid-state ECL biosensors involved an additional modification procedure on the electrode surface for immobilizing porous materials, resulting in time consumption and limited reproducibility.…”

“…Inspired by the abilities of porosity in electrochemistry, it was inferred that porosity was conducive to the shortening of spatial diffusion distance and the survival of radicals, both of which contributed to the subsequent recombination of electrons and holes for ECL emission. Recently, our group first prepared stannic oxide (SnO 2 ) nanocrystal xerogel with a porous structure, which enhanced the ECL by tenfold compared with that of discrete SnO 2 NCs . Zeng and colleagues selected covalent organic frameworks with a porous structure as microreactors to assemble tris­(2,2′-bipyridyl) ruthenium­(II) (Ru­(bpy) 3 2+ ), which realized the confinement-enhanced ECL .…”