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

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)32+) 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)32+/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)32+. 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.

Adsorption Features of Various Inorganic Materials for the Drug Removal from Water and Synthetic Urine Medium: A Multi-Technique Time-Resolved In Situ Investigation

Pharmaceutical active compounds, including hundreds of different substances, are counted among the emerging contaminants in waterbodies, whose presence raises a growing concern for the ecosystem. Drugs are metabolized and excreted mainly through urine as an unchanged active ingredient or in the form of metabolites. These emerging contaminants are not effectively removed with the technologies currently in use, making them a relevant environmental problem. This study proposes the treatment of urine and water at the source that can allow an easier removal of dissolved drugs and metabolites. The treatment of synthetic urine, with dissolved ibuprofen as a model compound, by adsorption, using various classes of inorganic materials, such as clays, hierarchical zeolites and ordered mesoporous silica (MCM-41), is presented. A multi-technique approach involving X-ray powder diffraction, solid-state NMR, UV-Vis and Raman spectroscopies was employed to investigate the adsorption process in inorganic adsorbents. Moreover, the uptake, the ensuing competition, the efficiency and selectivity as well as the packing of the model compound in ordered mesoporous silica during the incipient wetness impregnation process were all thoroughly monitored by a novel approach, involving combined complementary time-resolved in situ 1H and 13C MAS NMR spectroscopy as well as X-ray powder diffraction.