Carbon dots (CDs) were synthesized hydrothermally by mixing citric acid (CA) and an antifolic agent, sulfanilamide (SNM), employed for pH sensing and bacterial growth inactivation. Sulfanilamide is a prodrug; aromatic hetero cyclization of the amine moiety along with other chemical modifications produces an active pharmacological compound (chloromycetin and miconazole), mostly administered for the treatment of various microbial infections. On the other hand, the efficacy of the sulfanilamide molecule as a drug for antimicrobial activity was very low.
View Article and Find Full Text PDFMulticolor, fluorescent self-healing gels were constructed through reacting carbon dots produced from different aldehyde precursors with branched polyethylenimine. The self-healing gels were formed through Schiff base reaction between the aldehyde units displayed upon the carbon dots' surface and primary amine residues within the polyethylenimine network, generating imine bonds. The dynamic covalent imine bonds between the carbon dots and polymeric matrix endowed the gels with both excellent self-healing properties as well as high mechanical strength.
View Article and Find Full Text PDFPseudomonas aeruginosa is a highly virulent bacterium, particularly associated with the spread of multidrug resistance. Here we show that carbon dots (C-dots), synthesized from aminoguanidine and citric acid precursors, can selectively stain and inhibit the growth of P. aeruginosa strains.
View Article and Find Full Text PDFCarbon dots (C-dots) prepared through heating of aminoguanidine and citric acid enable bimodal (colorimetric and fluorescence) detection of nitric oxide (NO) in aqueous solutions. The C-dots retained the functional units of aminoguanidine, which upon reaction with NO produced surface residues responsible for the color and fluorescence transformations. Notably, the aminoguanidine/citric acid C-dots were noncytotoxic, making possible real-time and high sensitivity detection of NO in cellular environments.
View Article and Find Full Text PDFDetection of reactive oxygen species (ROS) is important in varied biological processes, disease diagnostics, and chemotherapeutic drug screening. We constructed a ROS sensor comprising an ascorbic-acid-based hydrogel encapsulating luminescent amphiphilic carbon-dots (C-dots). The sensing mechanism is based upon ROS-induced oxidation of the ascorbic acid units within the hydrogel scaffold; as a consequence, the hydrogel framework collapses resulting in aggregation of the C-dots and quenching of their luminescence.
View Article and Find Full Text PDFThe work in this report describes the syntheses, characterization, crystal structures and magnetic properties of eight linear trinickel(ii) compounds of the composition [Ni(II)3(L(sal-pyr))2(propionate)4] (), [Ni(II)3(L(sal-pyr))2(benzoate)4]·CH3CN (), [Ni(II)3(L(sal-pip))2(acetate)4]·2CH3CN (), [Ni(II)3(L(sal-pip))2(propionate)4] (), [Ni(II)3(L(sal-pip))2(benzoate)4]·CH2Cl2 (), [Ni(II)3(L(sal-mor))2(propionate)4] (), [Ni(II)3(L(sal-mor))2(benzoate)4]·3CH2Cl2 () and [Ni(II)3(L(sal-mor))2(o-Cl-benzoate)4]·2CH3CN·2H2O (), where HL(sal-pyr), HL(sal-pip) and HL(sal-mor) are the 1 : 1 condensation products of salicylaldehyde and 1-(2-aminoethyl)-pyrrolidine, 1-(2-aminoethyl)-piperidine and 4-(2-aminoethyl)-morpholine, respectively. One-half of the trinuclear core in each complex is symmetry related to the second part due to the presence of an inversion centre on the central metal ion and so the terminal nickelcentral nickelterminal nickel angle is 180°. The terminal and central nickel(ii) ions are triply bridged by a phenoxo, a μ1,1-carboxylato and a μ1,3-carboxylato moiety.
View Article and Find Full Text PDFThe bis(μ-phenoxo) Fe(III)Ni(II) compound [Fe(III)(N3)2LNi(II)(H2O)(CH3CN)](ClO4) (1) and the bis(μ-phenoxo)-μ-acetate/bis(μ-phenoxo)-bis(μ-acetate) Fe(III)Ni(II) compound {[Fe(III)(OAc)LNi(II)(H2O)(μ-OAc)](0.6)·[Fe(III)LNi(II)(μ-OAc)2](0.4)}(ClO4)·1.
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