Detection of Hg 2+ in aqueous solution by pyrazole derivative-functionalized Fe 3 O 4 @SiO 2 fluorescent probe

Novel magnetically separable anhydride-functionalized Fe3O4@SiO2@PEI-NTDA nanoparticles as effective adsorbents: synthesis, stability and recyclable adsorption performance for heavy metal ions

“…Aer the sol-gel reaction with TEOS in the presence of Fe 3 O 4 , a new strong adsorption peak appeared at around 1100 cm À1 , which was attributed to the stretching vibrations of Si-O-Si and Si-O-H; this indicates the presence and successful coating of the SiO 2 layer on the samples of Fe 3 O 4 @SiO 2 and their successive samples of Fe 3 O 4 @SiO 2 @PEI and Fe 3 O 4 @SiO 2 @PEI-NTDA. 35 It can be observed in the FT-IR spectra of Fe 3 O 4 and Fe 3 O 4 @-SiO 2 NPs that two peaks for the stretching vibration of hydroxyl (-OH) groups appear at 1609 cm À1 and 3440 cm À1 , indicating that there are hydroxyl groups on the surfaces of Fe 3 O 4 and Fe 3 O 4 @SiO 2 NPs. Aer the gra reaction with PEI, two new peaks at 2919 and 2840 cm À1 may be assigned to aliphatic C-H bonds; the bands at 1450 and 1320 cm À1 may belong to the stretching vibrations of C-H and C-N bonds, respectively.…”

1,3,4-Thiadiazol derivative functionalized-Fe3O4@SiO2 nanocomposites as a fluorescent probe for detection of Hg2+ in water samples

“…34 Recently, our group reported the successful design of two novel Fe 3 O 4 @SiO 2 uorescence probes with precise detection ability of mercury ion in water. 35,36 In continuation of our previous works, here, a novel uorescent probe is designed and graed on the Fe 3 O 4 @SiO 2 surface. A thiadiazole derivative is synthesized and applied as the uorophore functionalizing group on Fe 3 O 4 @SiO 2 nanocomposites and is used for detection of Hg 2+ in drinking water.…”

“…37 Certain factors such as suitable coordination geometry of ligand and ion, nitrogen affinity, and ion size and charge are effective in high selectivity of an ion. 35,45 In continue, more tests were conducted in order to show the potential application of the nanocomposite on detection of Hg 2+ ions in water samples.…”

Recent progress in chemosensors based on pyrazole derivatives

“…7b). 91 Upon the addition of Hg 2+ ions, probe 11 shows a decrease in the uorescence intensity band at 463 nm, when excited at 225 nm. A very low LOD was observed (7.6 nM) and the analysis can be done in water solutions.…”