A dual functional turn off florescence sensor using metal-organic framework for sensitive detection of aluminum(III) in aqueous solution.

Aluminum, classified as one of the toxic heavy metals, has a recommended daily consumption limit of 3-10 mg, as specified by the World Health Organization (WHO). Herein, the selective and sensitive aluminum(III) fluorescence sensor based on TMU-16 metal-organic frameworks (MOFs) in aqueous medium, is reported. A sensing pathway was found via the cation exchange between aluminum(III) and zinc(II) ions, and caused selectivity and sensitivity detection of aluminum(III) with a 5-100 ppm linear range and 1.99 ppm limit of detection (LOD). This sensor offers the advantage of accurately determining the concentration range of aluminum(III) ions. At low concentrations, only fluorescence quenching was observed, while at higher concentrations, fluorescence emission not only undergoes quenching but also exhibits a blue shift in wavelength. Notably, the sensor demonstrates no interference from cation solutions of mercury(II), zinc(II), nickel(II), lead(II), cobalt(II), cadmium(II), silver(I), chromium(III), and iron(III). Another significant feature of this sensor is its selectivity toward copper(II) and aluminum(III) ions, due to quenching fluorescence in the presence of copper(II) ion. The results presented the sensor's selectivity toward copper(II) at low concentrations and aluminum(III) at high concentrations.

Fabrication of an electrochemical aptasensor for the determination of sarcosine based on synthesized CuCo2O4 nanosheets.

Sarcosine (SRN) detection in body fluids is related to the diagnosis of prostate cancer. However, the development of SRN biosensors has been limited due to the low concentration of SRN in body fluids. Here, a new electrochemical strategy for selective and accurate determination of SRN in urine samples is reported. CuCo2O4 nanosheets (CuCo2O4 NSs) have been synthesized and used as a new platform in the design of efficient electrochemical aptasensors for prostate cancer diagnosis. As far as we know, CuCo2O4 NSs have not been used so far in electrochemical aptasensor design. The presence of CuCo2O4 NSs on the electrode surface as a platform improves the conductivity and surface area. Therefore, it can be very effective in improving the diagnostic performance of the electrochemical aptasensor. The linear concentration range and limit of detection (LOD) for this strategy were calculated to be 1 pM- 8 µM and 350 fM, respectively.

The effects of solvent and ultrasonic irradiation in synthesis of thallium(I) nano supramolecular polymers and use them as template for synthesis of thallium(III) oxide nanostructures with desirable morphology.

In order to study the effects of solvent and ultrasonic irradiation on formation of [Tl(HTar)]n (1) and/or [Tl2(Tar)]n (2), [H2Tar = (+)-tartaric acid] supramolecular polymers, we designed some experiments and synthesized four samples of 1 under the reaction of H2Tar and TlNO3 by sonochemical process and as the bulk samples. Nanostructures of compounds 1 and 2 as the bulk samples could be synthesized without ultrasonic irradiation, too. In the presence of ultrasonic waves, with acetonitrile solvent, more discrete nanoparticles were obtained. These four samples have been used as new precursors for preparation of thallium(III) oxide nanostructures via solid-state thermal decomposition process. There is a direct relationship between the morphology of initial precursors and resulting thallium(III) oxide nanostructures. These nanostructures were characterized by IR spectroscopy, X-ray powder diffraction (XRD) and Scanning Electron Microscopy (SEM).

Synthesis and application of ion-imprinted polymer for extraction and pre-concentration of iron ions in environmental water and food samples.

In this work, a novel Fe(III) ion imprinted polymer as a sorbent for extraction of iron ions from different samples was synthesized. Precipitation of thermal copolymerization was used for preparation of polymeric sorbent. In this technique, methacrylic acid, ethylene glycoldimethacrylate, 2,2'-azobisisobutyronitrile and (DHBPT)2 {(DHBPT)2=3,6-bis (3,5-dimethyl-1-H-pyrzol-1-yl)-1,2-dihydro-1,2,4,5-tetrazine)} were used as monomer, cross-linker, initiator and ligand, respectively, in the presence of Fe(III) ions and ethanol as a porogenic solvent. Moreover, control polymer (NIP) particles were similarly prepared without the Fe(III) ions. XRD, FT-IR, SEM and nitrogen adsorption-desorption techniques have been used to characterization of these prepared polymeric samples. Iron ion imprinted polymer particles, abbreviated as Fe(III)-IIP, were leached with 50 mL of HCl (50% (v/v)). Absorption capacity for ion imprinted polymer was calculated about 40.41 mg·g(-1). Per-concentration of iron ion was investigated as a function of pH, weight of IIP, adsorption and desorption times, and volumes of sample. FAAS technique was used to determination of Fe(III) ion in the foods and waters samples.