A highly selective and sensitive ratiometric fluorescent probe for quantitative detection of Al(III) in different natural matrices.

A highly selective and sensitive assay of Al(III) using ratiometric fluorescence enhancement is reported in an aqueous solution. The probe (named RS5) exhibits a red-shift of 54 nm upon binding with Al(III) ion. The significant enhancement response of RS5 at 481 nm is attributed to the formation of a 1:1 complex between the probe and Al(III), wherein RS5 acts as a tridentate NNN-donor ligand. The complexation process is ascertained by1H,13C, and27Al NMR and HR-MS spectral techniques. The binding constant of the complex is determined to be 1.3 × 105M-1. The ratiometric change in fluorescence upon complexation with Al(III) is ascribed to an increase in intramolecular charge transfer (ICT) transition along with chelation enhanced fluorescence (CHEF) processes. The probe can be applied for monitoring Al(III) in a pH range of 6-8. The limit of detection (LOD) of RS5 for the examination of Al(III) is found to be 0.3µM. With an aim to understand the sensing behavior of RS5, the optical properties of the probe and its Al(III) complex are investigated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods. The probe is successfully employed for the determination of Al(III), with very high recovery percentages, in natural matrices like deep well water, tap water, drinking water, pond water, river water, bovine serum albumin (BSA) solution and blood serum.

2-Aminophenols based Schiff bases as fluorescent probes for selective detection of cyanide and aluminium ions - Effect of substituents.

Three Schiff base based probes are designed and synthesized by facile condensation of a commercially available fluorophore 2,6-diformyl-4-tert-butylphenol with 4-nitro-2-aminophenol (KP1), 2-aminophenol (KP2) and 4-tert-butyl-2-aminophenol (KP3) and are characterized using various spectral techniques. The probes exhibit high selectivity and sensitivity CN- and Al(III) ions with striking fluorescent signaling responses in H2O-DMSO (1:1, v/v) medium. The mechanism of the probes' detection of CN involves deprotonation of the phenolic OH group(s) followed by nucleophilic addition of CN- onto imine C-atom. The 1H NMR chemical shifts of the OH protons of 2-aminophenol moiety exhibits a linear correlation with the Hammett's substituent constants (σp), yielding a positive reaction constant (ρ). In KP1, the electron-withdrawing nitro substituent polarizes the imine bond to a larger extent than in KP2, resulting in easier addition of CN- to imine C-atom. The electron releasing tert-Bu substituent in KP3 produces the opposite effect leading to a sluggish addition reaction. The separately populated HOMO and LUMO in KP1 and a relatively lower HOMO-LUMO energy gap indicate substantial intramolecular charge transfer (ICT) character, leading to weak fluorescence emission. The large reduction in HOMO-LUMO energy gap, in KP1, upon addition of cyanide is responsible for the greater enhancement in fluorescence with blue shift upon addition of CN-. Formation of tetrahedral Probe-Al(III) complex prevents the isomerization of imine bond, leading to enhancement in fluorescence and contribution from chelation enhanced fluorescence. As these probes show very low limits of detection of these ions, their practical utility has also been demonstrated.

3-Hydroxy-2-naphthoic hydrazide as a probe for fluorescent detection of cyanide and aluminium ions in organic and aquo-organic media and its application in food and pharmaceutical samples.

The commercially available fluorophore, 3-hydroxy-2-naphthoic hydrazide (RS2), has rationally been selected for the study, which displays a rapid fluorescent response and high sensitivity for CN- and Al(III) ions in neat DMSO and H2O-DMSO (1:1 v/v) media. The addition of CN- to RS2 triggers an enhancement in fluorescence at 505 nm (green fluorescence), while the addition of Al(III) increases the fluorescence of the probe with a blue-shift of emission maximum by 25 nm (bluish-green fluorescence). The probe's action was investigated by 1H NMR titrations that indicate deprotonation of OH and NH moieties by these ions. 27Al NMR of RS2-Al(III) complex suggests an octahedral geometry for the complex. The sensitivity of the fluorescent-based assays in aq. DMSO medium, 0.8 µM for CN- and 1.9 µM for Al(III) ions are far below the limits in the World Health Organization guidelines for drinking water. RS2 detects Al(III) by the chelation-enhanced fluorescence (CHEF) mechanism. Besides, RS2 was successfully applied to detect CN- and Al(III) ions in food materials and pharmaceutical samples, respectively.

Therapeutic evaluation of homeopathic treatment for canine oral papillomatosis.

AIM: A study was conducted to evaluate the ameliorative potential of homeopathic drugs in combination (Sulfur 30C, Thuja 30C, Graphites 30C, and Psorinum 30C) in 16 dogs affected with oral papillomatosis which was not undergone any previous treatment. MATERIALS AND METHODS: Dogs affected with oral papillomatosis, which have not undergone any initial treatment and fed with a regular diet. Dogs (total=16) were randomly divided into two groups, namely, homeopathic treatment group (n=8) and placebo control group (n=8). Random number table was used for allocation. Homeopathic combination of drugs and placebo drug (distilled water) was administered orally twice daily for 15 days. Clinical evaluation in both groups of dogs was performed by the same investigator throughout the period of study (12 months). Dogs were clinically scored for oral lesions on days 0, 5, 7, 10, 15, 20, 25, 30, 45, 60, 90, 120, and 150 after initiation of treatment. RESULTS: The homeopathic treatment group showed early recovery with a significant reduction in oral lesions reflected by clinical score (p<0.001) in comparison to placebo-treated group. Oral papillomatous lesions regressed in the homeopathic group between 7 and 15 days, whereas regression of papilloma in the placebo group occurred between 90 and 150 days. The homeopathic treated group was observed for 12 months post-treatment period and no recurrence of oral papilloma was observed. CONCLUSION: The current study proves that the combination of homeopathy drugs aids in fastening the regression of canine oral papilloma and proved to be safe and cost-effective.