Umesh D. Patil

Anion selective chromogenic and fluorogenic chemosensor and its application in breast cancer live cell imaging

A novel Schiff base receptor (L) bearing catechol and phenol groups was synthesized and characterized by various spectral (FTIR, 1H NMR and mass) data. The anion recognition ability of L was investigated by experimental (UV-Vis, fluorescence and 1H NMR) and theoretical (B3LYP/6-31G**) methods. Among the tested anions, the receptor L showed both naked-eye detectable color change from light-yellow to intense brownish-yellow and spectral (hyperchromic shift at 450 nm and ‘turn-on’ fluorescence at 480 nm) changes selectively towards F− and AcO− in DMSO and mixed DMSO–H2O medium because of the formation of a hydrogen bonded anion-receptor complex followed by the deprotonation of L. The receptor L was tested for live breast cancer cell imaging and can be applied to the breast tumour diagnosis.

Bioimaging application of a novel anion selective chemosensor derived from vitamin B6 cofactor.

The detection of intracellular fluoride was achieved by a novel Schiff base chemosensor derived from vitamin B6 cofactor (L) using fluorescence imaging technique. The sensor L was synthesized by condensation of pyridoxal phosphate with 2-aminothiophenol. The anion recognition ability of L was explored by UV-Vis and fluorescence methods in DMSO and mixed DMSO-H2O system. The sensor L showed both naked-eye detectable color change from colorless to light green and remarkable fluorescence enhancement at 500 nm in the presence of F(-) and AcO(-). The anion recognition was occurred through the formation of hydrogen bonded complexes between these anions and L, followed by the partial deprotonation of L. The detection limit of L for the analysis of F(-) and AcO(-) was calculated to be 1.88 μM and 9.10 μM, respectively. Finally, the detection of cytoplasmic fluoride was tested using human cancer cell HeLa through fluorescence imaging.

The Amidine Based Colorimetric Sensor for Fe 3+ , Fe 2+ , and Cu 2+ in Aqueous Medium

An amidine based chemosensor AM-1 was synthesized and characterized by various spectroscopic (FT-IR, 1H-NMR and mass) data and elemental analyses. Sensor AM-1 exhibited high selectivity and sensitivity towards Fe3+, Fe2+ and Cu2+ in the presence of other surveyed ions (such as Sr2+, Cr3+, Co2+, Ni2+, Zn2+, Ag+, Al3+, Ba2+, Ca2+, Cd2+, Cs+, Hg2+, K+, Li+, Mg2+, Mn2+, Na+ and Pb2+) with a distinct naked-eye detectable color change and a shift in the absorption band. Moreover, the emission of AM-1 was quenched selectively only in the presence of Fe3+.

A uracil nitroso amine based colorimetric sensor for the detection of Cu2+ ions from aqueous environment and its practical applications

A simple uracil nitroso amine based colorimetric chemosensor (UNA-1) has been synthesized and screened for its cation recognition ability. Sensor UNA-1 exhibited a high sensitivity and selectivity towards Cu2+ ions in aqueous medium in the presence of a wide range of other competing cations (Ag+, Al3+, Ba2+, Ca2+, Cd2+, Co2+, Cr3+, Cs+, Fe2+, Fe3+, Li+, Mg2+, Mn2+, Na+, Ni2+, Pb2+, Zn2+, Hg2+ and Sr2+). With Cu2+, the sensor UNA-1 gave a distinct color change from colorless to dark yellow by forming a complex of 1 : 1 stoichiometry. Furthermore, sensor UNA-1 was successfully utilized in the preparation of test strips and supported silica for the detection of Cu2+ ions from aqueous environment.

A Convenient, TiCl4/SnCl4-Mediated Synthesis of N-Phenyl or N-Aryl Benzamidines and N-Phenylpicolinamidines

A new, TiCl4-or SnCl4-mediated, solvent-free method was developed for the synthesis of N-Aryl benzamidines and N-phenylpicolinamidines, in moderate-to-good yield, using suitable amines and nitriles as starting materials.