Vertically Ordered Mesoporous Silica-Nanochannel Film-Equipped Three-Dimensional Macroporous Graphene as Sensitive Electrochemiluminescence Platform.

Jiawei Gong,Fengna Xi,Xueting Lin,Hongliang Tang,Fei Yan,Huaxu Zhou,Jiyang Liu,Xuan Luo,Kailong Wang

doi:10.3389/fchem.2021.770512

Abstract

Three-dimensional (3D) electrochemiluminescence (ECL) platform with high sensitivity and good anti-fouling is highly desirable for direct and sensitive analysis of complex samples. Herein, a novel ECL-sensing platform is demonstrated based on the equipment of vertically ordered mesoporous silica-nanochannel films (VMSF) on monolithic and macroporous 3D graphene (3DG). Through electrografting of 3-aminopropyltriethoxysilane (APTES) onto 3DG as molecular glue, VMSF grown by electrochemically assisted self-assembly (EASA) method fully covers 3DG surface and displays high stability. The developed VMSF/APTES/3DG sensor exhibits highly sensitized ECL response of tris(2,2′-bipyridyl) ruthenium (Ru (bpy)3 2+) taking advantages of the unique characteristics of 3DG (high active area and conductivity) and VMSF nanochannels (strong electrostatic enrichment). The VMSF/APTES/3DG sensor is applied to sensitively detect an important environmental pollutant (4-chlorophenol, with limit of detection or LOD of 30.3 nM) in term of its quenching effect (ECL signal-off mode) toward ECL of Ru (bpy)3 2+/tri-n-propylamine (TPrA). The VMSF/APTES/3DG sensor can also sensitively detect the most effective antihistamines chlorpheniramine (with LOD of 430 nM) using ECL signal-on mode because it acts as co-reactant to promote the ECL of Ru (bpy)3 2+. Combined with the excellent antifouling ability of VMSF, the sensor can also realize the analysis of actual environmental (lake water) and pharmaceutical (pharmacy tablet) samples. The proposed 3D ECL sensor may open new avenues to develop highly sensitive ECL-sensing platform.

Highlights

Solid-state nanofilms have recently been widely used in the fields of molecular sieves, energy conversion, nanofluidics, and biosensing owing to their adjustable nanopores, intelligent control of molecular transport, and high device integration capabilities (Huang et al, 2016; Dong et al, 2020; Garbayo et al, 2021)
We present a novel 3D ECL sensing platform based on the equipment of vertically ordered mesoporous silica-nanochannel films (VMSF) on porous 3D graphene foam electrode (3DG)
The energy dispersive spectrometer (EDS) characterization shows high content of C atoms

Summary

Introduction

Solid-state nanofilms have recently been widely used in the fields of molecular sieves, energy conversion, nanofluidics, and biosensing owing to their adjustable nanopores, intelligent control of molecular transport, and high device integration capabilities (Huang et al, 2016; Dong et al, 2020; Garbayo et al, 2021). On the one hand, derived from its silanol groups (pKa ∼ 2), VMSF usually has an anionic nature under normal pH conditions. This charge characteristic accelerates the transfer of positively charged molecules to the electrode surface, thereby improving the detection sensitivity. VMSF shows good anti-fouling ability because the ultrasmall nanochannels can effectively inhibit the interference of co-existing large substances (e.g., proteins), leading to good signal stability in analysis of complex samples (e.g., whole blood, biological fluids, environmental, or food samples) (Yan and Su, 2016; Zhou et al, 2018; Duan et al, 2021; Gamero-Quijano et al, 2021).

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