In Situ Synthesis of Gold Nanoparticles/Metal–Organic Gels Hybrids with Excellent Peroxidase-Like Activity for Sensitive Chemiluminescence Detection of Organophosphorus Pesticides

Abstract

Until now, despite much progress in the study of metal-organic gels (MOGs), the modification of transition-metal containing MOGs with noble metal nanoparticles (NPs) is far from fully developed. Herein, iron-based MOGs nanosheet hybrids with gold NPs (AuNPs) immobilization were first synthesized by a facile in situ grown strategy at ambient conditions. It is found that the as-prepared AuNPs/MOGs (Fe) hybrids exhibited enhanced mimicking peroxidase-like activity, making them endowed with outstanding performance in chemiluminescence (CL) field in the presence of HO. The remarkable CL enhancement by AuNPs/MOGs (Fe) hybrids was attributed to the modification of AuNPs on MOGs (Fe) nanosheets, which could synergistically accelerate the CL reaction by speeding up the generation of OH, O, and O. Accordingly, a sensitive CL detection of organophosphorus pesticides was successfully achieved by the AuNPs/MOGs (Fe) hybrids CL enhancing system in the range of 5-800 nM with a detection limit of 1 nM. We envision that this highly active and novel enzyme mimetic catalyst can be applicable to other extended AuNPs/MOGs (Fe) hybrid-based CL systems for sensitive detection of various analytes.

Effect of Substrates on Catalytic Activity of Biogenic Palladium Nanoparticles in C–C Cross-Coupling Reactions

“…Various approaches for generation of in situ NPs of Au, Ag, Cu, and Pd have been reported. 9−14 Chemical methods for generation of NPs are associated with toxic byproducts and uneconomical issues. From the green chemistry point of view, environmentally benevolent alternative reducing agents for the synthesis of NPs are in great demand.…”

A Guanidine-Based Superbase as Efficient Chemiluminescence Booster

“…In contrast to the charge-transfer-induced decomposition mechanism of the dioxetane-CL-reaction 42 , the CL-reaction of luminol is triggered by reactive oxygen species (ROS) 29,45,46 . Typical ROS in the luminol-CL-reaction are the hydroxyl radical • OH, the superoxide anion radical O 2 •− or singlet oxygen 1 O 2 29,47,48 . To identify the involved ROS in the new luminol-TBD-system, spin-trap-experiments with the radical scavengers L-ascorbic acid (AA), sodium azide (NaN 3 ), superoxide dismutase (SOD), thiourea (TU), 2,2,6,6- tetramethyl-4-piperidone (TMPD) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) were carried out 48 .…”

“…4a), proving the generation of ROS in the CL-reaction of the luminol-TBD-system. While SOD is known to be a specific radical scavenger for O 2 •− , NaN 3 and TU are less specific, reacting with • OH, O 2 •− and 1 O 2 48–51 . Therefore, electron-paramagnetic resonance (EPR) spectroscopy was used to distinguish between the possible involved ROS.…”

“…Due to the short lifetime of the ROS, DMPO and TMPD are used as spin-trap-compounds. Both compounds are not EPR active, unless they react with ROS to form the EPR-active nitroxide radicals, which possess a longer lifetime than • OH, O 2 •− or 1 O 2 48 . TMPD is a well-known spin-trap molecule for 1 O 2 , while DMPO has been used for detection of • OH and O 2 •− .…”

Supported Metal Nanoparticles in Metal‐Organic Monoliths for Assembly of a Catalytic Microfluidic Reactor

“…Metal‐organic gels (MOGs) are an attractive catalogue of porous materials which are self‐assembled from metal ions and organic ligands through metal–organic coordination, and have found applications in catalysis [27–31] . As a catalogue of hierarchically porous materials, MOGs provide both meso‐/macropores for mass transfer channels and micropores for the immobilization of catalytically active centers [32–34] . Additionally the organic linkers can be readily modified with diverse functional groups to change the physiochemical properties.…”