Colorimetric/fluorescent/Raman trimodal sensing of zinc ions with complexation-mediated Au nanorod

A dual-responsive nanozyme sensor with ultra-high sensitivity and ultra-low cross-interference towards metabolic biomarker monitoring

Accurate, sensitive and selective detection of metabolic biomarkers in biofluids are of vital significance for health self-monitoring and chronic disease prevention. Here, for the first time, a smart dual-responsive nanozyme sensor (DNS) was developed for simultaneous analysis of glucose and caffeine utilizing stimuli-responsive yolk-shell gold nanoparticles (GNPs)-embedded MIL-53 (Al) (GNPs@MIL-53) structures. After the introduction of glucose, GNPs@MIL-53 displays excellent glucose oxidase (GOx)-like activity to induce the conversion of glucose to gluconic acid and H₂O₂. H₂O₂ can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) with the generation a bright-blue color, enabling in-field visualization and surface enhanced Raman scattering (SERS) detection of glucose. Upon the addition of caffeine, 2-aminoterephthalic acid modified MIL-53 can react with the caffeine to form intermolecular hydrogen-bonded complexes, leading to strong cyan fluorescence and significant Raman enhancements. The DNS with multi-channel signal outputs can simultaneously determine glucose and caffeine at concentrations of as low as 3 × 10^-8 M and 1.2 × 10^-11 M, respectively. Importantly, the DNS-based analytical system not only enables visual discrimination and accurate assay of glucose and caffeine in biofluids, but also exhibits negligible cross-interference between glucose and caffeine determination. The combined characteristics of high selectivity, enhanced accuracy and superior quantitative performance make our platform suitable for the point-of-care monitoring of chronic-disease-related metabolic biomarkers.

The Versatility in the Applications of Dithiocarbamates

Dithiocarbamate ligands have the ability to form stable complexes with transition metals, and this chelating ability has been utilized in numerous applications. The complexes have also been used to synthesize other useful compounds. Here, the up-to-date applications of dithiocarbamate ligands and complexes are extensively discussed. Some of these are their use as enzyme inhibitor and treatment of HIV and other diseases. The application as anticancer, antimicrobial, medical imaging and anti-inflammatory agents is examined. Moreover, the application in the industry as vulcanization accelerator, froth flotation collector, antifouling, coatings, lubricant additives and sensors is discussed. The various ways in which they have been employed in synthesis of other compounds are highlighted. Finally, the agricultural uses and remediation of heavy metals via dithiocarbamate compounds are comprehensively discussed.