Luminescent micelles are extensively studied molecular scaffolds used in applied supramolecular chemistry. These are particularly important due to their uniquely organized supramolecular structure and chemically responsive physical and optical features. Various luminescent tags can be incorporated with these amphiphilic micelles to create efficient luminescent probes that can be utilized as “chemical noses” (sensors) for toxic and hazardous materials, bioimaging, drug delivery and transport, etc. Due to their amphiphilic nature and well-defined reorganized self-assembled geometry, these nano-constructs are desirable candidates for size and shape complementary guest binding or sensing a specific analyte. A large number of articles describing micellar fluorogenic probes are reported, which are used for cation/anion sensing, amino acid and protein sensing, drug delivery, and chemo-sensing. However, this particular review article critically summarizes the sensing application of nitroaromatic (e.g., trinitrotoluene (TNT), trinitrobenzene (TNB), trinitrophenol (TNP), dinitrobenzene (DNB), etc.) and nitramine explosives (e.g., 1,3,5-trinitro-1,3,5-triazinane, trivially named as “research department explosive” (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetrazocane, commonly known as “high melting explosive” (HMX) etc.). A deeper understanding on these self-assembled luminescent “functional materials” and the physicochemical behavior in the presence of explosive analytes might be helpful to design the next generation of smart nanomaterials for forensic applications. This review article will also provide a “state-of-the-art” coverage of research involving micellar–explosive adducts demonstrating the intermolecular charge/electron transfer (CT/ET) process operating within the host–guest systems.
Synthesis of luminescent metal cluster for selective sensing of speci c analyte with detail mechanistic understanding is very important for real world applications as well as for developing new emissive materials. In the present work, we have synthesized L-glutathione stabilized gold (Au-SG) and gold-silver bimetallic (AuAg-SG) clusters under identical experimental conditions with orange red emissive characteristics for both. Detail photo physical analysis reveals that both clusters are phosphorescent in nature with moderate quantum yield of 7% and 19% for Au-SG and AuAg-SG respectively and their excited state lifetime values are in the range of 1-2 µs. While Au-SG cluster showed luminescence quenching response (turn-off) in presence of Fe 3+ and Hg 2+ ions, AuAg-SG cluster showed turn-off response for Cu 2+ , Fe 3+ and Hg 2+ , but luminescent enhancement (turn-on) response for Cd 2+ ions. The highest detection limit obtained for Cu 2+ ion by AuAg-SG cluster is 20 nM while for Cd 2+ ion it is 75 nM. From TCSPC and DLS measurements we postulated that except Cd 2+ , all other metal ions cause aggregation of clusters through ligation with SG ligands while Cd 2+ ion does not induce any cluster aggregation but binds to cluster surface atoms. The near constant life time values of both clusters during gradual addition of respective metal ions con rms static quenching/enhancement process through formation of stable ground state adducts.
Synthesis of luminescent metal cluster for selective sensing of specific analyte with detail mechanistic understanding is very important for real world applications as well as for developing new emissive materials. In the present work, we have synthesized L-glutathione stabilized gold (Au-SG) and gold-silver bimetallic (AuAg-SG) clusters under identical experimental conditions with orange red emissive characteristics for both. Detail photo physical analysis reveals that both clusters are phosphorescent in nature with moderate quantum yield of 7% and 19% for Au-SG and AuAg-SG respectively and their excited state lifetime values are in the range of 1–2 µs. While Au-SG cluster showed luminescence quenching response (turn-off) in presence of Fe3+ and Hg2+ ions, AuAg-SG cluster showed turn-off response for Cu2+, Fe3+ and Hg2+, but luminescent enhancement (turn-on) response for Cd2+ ions. The highest detection limit obtained for Cu2+ ion by AuAg-SG cluster is 20 nM while for Cd2+ ion it is 75 nM. From TCSPC and DLS measurements we postulated that except Cd2+, all other metal ions cause aggregation of clusters through ligation with SG ligands while Cd2+ ion does not induce any cluster aggregation but binds to cluster surface atoms. The near constant life time values of both clusters during gradual addition of respective metal ions confirms static quenching/enhancement process through formation of stable ground state adducts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.