Pinkesh G. Sutariya

Fluorescence switch on-off-on receptor constructed of quinoline allied calix[4]arene for selective recognition of Cu2+ from blood serum and F- from industrial waste water.

A novel PET with ICT based substituted calix[4]arene fluroionophore was synthesized and used for detection of Cu(2+) and F(-) by emission spectra. The detection limit of the synthesized receptor was found to be 4.16 nM for Cu(2+) and 2.15 nM for F(-). Moreover, this probe has been applied for recognition of Cu(2+) in blood serum and F(-) from waste water.

Melamine modified gold nanoprobe for “on-spot” colorimetric recognition of clonazepam from biological specimens

Inexpensive, rapid, and reliable methods of detection are crucial to the control of toxicological investigations. Here we report a highly sensitive, selective and cost effective method for the detection of trace amounts of clonazepam based on gold nanoparticles (AuNPs) in the presence of melamine. Hydrogen bonding interactions between clonazepam and melamine resulted in the aggregation of AuNPs and a consequent color change of AuNPs from wine red to blue. The results showed that the absorption ratio (A636/A552) was linear for clonazepam concentrations in the range of 10 × 10(-8) to 1.0 × 10(-9) M (R(2) = 0.999). The detection limit was 8.9 × 10(-10) M (S/N = 3), which was much lower than that of most existing methods. Coexisting substances including alprazolam, diazepam, nitrazepam and lorazepam did not affect the determination of clonazepam. The sensor developed by this new approach could be used as a spot test and a good alternative means for on-site and real time screening of clonazepam. This proposed scheme was also supported by the use of real samples such as skeletal remains and blood to illustrate the applicability of the developed nanosensor by a series of experiments.

A highly efficient PET switch on–off–on fluorescence receptor based on calix[4]arene for the selective recognition of Cd2+ and Sr2+

A novel PET (photoinduced electron transfer) based substituted calix[4]arene fluoroionophore has been synthesized and used for the selective recognition of Cd(2+) and Sr(2+) by emission spectra. The detection limit of the synthesized receptor was found to be 0.94 pM for Cd(2+) and 1.04 pM for Sr(2+). Moreover, this probe has been applied to the recognition of Cd(2+) and Sr(2+) in waste water.

Lab-on-phone citrate-capped silver nanosensor for lidocaine hydrochloride detection from a biological matrix

In the present investigation, we applied the application potential of nanomaterials and smartphone analysis to develop a specific, sensitive and portable method. In this study, we report a silver nanoparticles-based colorimetric nanosensor for the determination of lidocaine hydrochloride (LHC) up to 0.05 ng mL−1 with good linear correlation in the range from 0.1 to 4.5 ng mL−1 with a correlation coefficient of 0.9914. Coexisting substances, including acetaminophen, diazepam, nitrazepam, lorazepam, zolpidem, atropine, bupivacaine, clonazepam and morphine did not interfere in the determination of LHC. The developed sensor proved to be a smart alternative lab-on-phone device, which would help in the on-the-spot determination of LHC in forensic toxicological drug screening. Herein, we utilized easily accessible vitreous humor, which is often unnoticed for toxicological drug screening along with blood for real sample analysis.

Synthesis, mesomorphism and dielectric behaviour of novel basket shaped scaffolds constructed on lower rim azocalix[4]arenes

A newly designed series of lower rim azocalix[4]arene basket type mesogens were synthesised and fully characterized. The proposed supramolecular organization displays needle shaped, rod like, focal conic and schlieren textures. These compounds were studied for their dielectric properties in the frequency range 100 Hz–2 MHz at variable temperatures (50–110 °C).

The influence of linking group in exterior point on mesogenic properties of the basket moulded molecules: calix[4]arene

Novel basket-shaped molecules having calix[4]arene as central rigid core possessing azomaterial in outer space unit in the lengthening arm were synthesised and characterised by elemental analysis and different spectroscopic methods such as Fourier Transform Infrared (FT-IR), electron spin ionization (ESI)-MASS, 1H nuclear magnetic resonance (NMR) and 13C NMR. Mesomorphism behaviour of novel materials was studied using optical polarising microscopy, differential scanning calorimetry and higher-temperature powder X-ray diffraction method to confirm smectic C phase. In most of the compounds, we found rod-like mosaic texture and focal conic textures of smectic C phases. Nematic phases were also quite often found in materials during cooling and heating stage from isotropic phases. The dielectric measurements have been carried out for the determination of real and imaginary parts of the permittivity of the newly designed scaffolds. These studies will give adequate prospects in the field of supramolecular system, especially in calixarene organisation to explore new epoch of calixarene-based liquid crystals with different linking groups.

Analytical detection and method development of anticancer drug Gemcitabine HCl using gold nanoparticles.

A simple, rapid, cost effective and extractive UV spectrophotometric method was developed for the determination of Gemcitabine HCl (GMCT) in bulk drug and pharmaceutical formulation. It was based on UV spectrophotometric measurements in which the drug reacts with gold nanoparticles (AuNP) and changes the original colour of AuNP and forms a dark blue coloured solution which exhibits absorption maximum at 688nm. The apparent molar absorptivity and Sandells sensitivity coefficient were found to be 3.95×10(-5)lmol(-1)cm(-1) and 0.060μgcm(-2) respectively. Beers law was obeyed in the concentration range of 2.0-40μgml(-1). This method was tested and validated for various parameters according to ICH guidelines. The proposed method was successfully applied for the determination of GMCT in pharmaceutical formulation (parental formulation). The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation <2%). As it is simple, cheap and less time consuming, it can be suitably applied for the estimation of GMCT in dosage forms.

Design, synthesis and characterization of quinoline–pyrimidine linked calix[4]arene scaffolds as anti-malarial agents

In this paper, we report a series of quinoline-pyrimidine linked calix[4]arene derivatives functionalized with 8-amino quinoline, 5-amino quinoline, 8-hydroxy quinoline, 2-amino pyrimidine and 4-amino 3-methyl quinoline. The synthesized compounds were purified and characterized by elemental analysis, FT-IR, 1H NMR and ESI-MS and screened for their anti-malarial activity against plasmodium falciparum strains. Two synthesized compounds with 8-hydroxy quinoline and 2-amino pyrimidine substituents showed good antimalarial activity with IC50 0.073 and 0.043 µg/ml respectively which is comparable with the standard drug chloroquine. The present study provides valuable information for developing calix[4]arene conjugates quinoline-pyrimidine based derivatives as an effective antimalarial agents.Graphical AbstractIn this paper, we report a series of quinoline-pyrimidine linked calix [4]arenes derivatives functionalised with 8-amino quinoline, 5-amino quinoline, 8-hydroxy quinoline, 2- amino pyrimidine and 4-amino 3-methyl quinoline and screened for antimalarial activity. Two synthesized compounds with 8-hydroxy quinoline and 2-amino pyrimidine substituents showed good antimalarial activity with IC50 0.073 and 0.043 µg/mL respectively, which is comparable with the standard drug chloroquine. The present study provides valuable information for developing calix[4]arene conjugates quinoline-pyrimidine derivatives.

Thioctic acid modified gold nanoparticles for highly specific and ultrasensitive detection of lanthanum in soil and water

We report ultrasensitive ligand to metal charge transfer (LMCT) based thioctic acid modified gold nanoparticles for the detection of lanthanum ion with excellent sensitivity (50 nM) and selectivity over other cations.

A pyrenyl linked calix[4]arene fluorescence probe for recognition of ferric and phosphate ions

A pyrenyl linked calix[4]arene fluroionophore has been synthesized and used as a ditopic chemosensing ensemble for Fe3+ and H2PO4− using emission spectra. The detection limit of the synthesized receptor was found to be 0.88 pM for Fe3+ and 1.11 pM for H2PO4−. Moreover, this probe has been applied for recognition of Fe3+ in blood serum and H2PO4− in waste water.