Water dispersible silver nanoparticles（AgNps） were prepared using thiacalix[4]arene tetrahydrazide（TCTH） as a reducing and stabilizing agent.TCTH-AgNps were characterized by surface plasmon resonance（SPR）,transm...Water dispersible silver nanoparticles（AgNps） were prepared using thiacalix[4]arene tetrahydrazide（TCTH） as a reducing and stabilizing agent.TCTH-AgNps were characterized by surface plasmon resonance（SPR）,transmission electron microscopy（TEM） and energy dispersive X-ray（EDX）.Relatively uniform 20 nm spherical particles of TCTH-AgNps were efficiently formed over a pH range of 5-9 and from 10-40 ℃.The interaction behavior of TCTH-AgNps with different amino acids was investigated using spectrophotometry and spectrofluorimetry.Among the amino acids tested,only tryptophan and histidine showed fluorescence quenching and fluorescence enhancement,respectively.The linear detection range by Stern-Volmer plot was 5 nmol/L to 0.48 μmol/L for tryptophan and 4 nmol/L to 0.54 μmol/L for histidine.TCTH-AgNps were able to effectively reduce the levels of gram-positive bacteria,gram-negative bacteria,and fungi.These properties argue for the potential use of TCTH-AgNps as detectors of histidine and tryptophan and as antibiotics.展开更多
A simple and quick method for the synthesis of water dispersible stable silver nanoparticles has been developed. Calix[4]pyrrole octahydrazide （CPOH）, has been successfully used as a reducing as well as stabilizing ...A simple and quick method for the synthesis of water dispersible stable silver nanoparticles has been developed. Calix[4]pyrrole octahydrazide （CPOH）, has been successfully used as a reducing as well as stabilizing agent for the synthesis of silver nanoparticles. CPOH-AgNps have been duly characterized by SPR, PSA, TEM and EDX-ray. The ability of CPOH-AgNps as selective and sensitive sensor for various ions （Pb（Ⅱ）, Cd（II）, Mn（Ⅱ）, Fe（Ⅲ）, Ni（Ⅱ）, Zn（Ⅱ）, Hg（Ⅱ）, Co（Ⅱ）, Cu（Ⅱ）） by colorimetry and spectrofluorimetry has been explored. CPOH-AgNps were found to be selective only for Hg（Ⅱ） ions. Nanomolar concentration of Hg（Ⅱ） ions can also be determined by spectrofluorimetry by increase in fluorescence intensity. Linear range of detection of Hg（Ⅱ） ions in water was found to be from 1nmol/L to mol/L. The method has been successfully applied for determination of Hg（Ⅱ） ions in ground water and industrial effluent waste water samples.展开更多
基金the financial assistance provided by University Grant Commission (UGC), New Delhi
文摘Water dispersible silver nanoparticles（AgNps） were prepared using thiacalix[4]arene tetrahydrazide（TCTH） as a reducing and stabilizing agent.TCTH-AgNps were characterized by surface plasmon resonance（SPR）,transmission electron microscopy（TEM） and energy dispersive X-ray（EDX）.Relatively uniform 20 nm spherical particles of TCTH-AgNps were efficiently formed over a pH range of 5-9 and from 10-40 ℃.The interaction behavior of TCTH-AgNps with different amino acids was investigated using spectrophotometry and spectrofluorimetry.Among the amino acids tested,only tryptophan and histidine showed fluorescence quenching and fluorescence enhancement,respectively.The linear detection range by Stern-Volmer plot was 5 nmol/L to 0.48 μmol/L for tryptophan and 4 nmol/L to 0.54 μmol/L for histidine.TCTH-AgNps were able to effectively reduce the levels of gram-positive bacteria,gram-negative bacteria,and fungi.These properties argue for the potential use of TCTH-AgNps as detectors of histidine and tryptophan and as antibiotics.
基金financial assistance provided by University Grants Commission (New Delhi. India), GUJCOST (Gandhinagar, India)
文摘A simple and quick method for the synthesis of water dispersible stable silver nanoparticles has been developed. Calix[4]pyrrole octahydrazide （CPOH）, has been successfully used as a reducing as well as stabilizing agent for the synthesis of silver nanoparticles. CPOH-AgNps have been duly characterized by SPR, PSA, TEM and EDX-ray. The ability of CPOH-AgNps as selective and sensitive sensor for various ions （Pb（Ⅱ）, Cd（II）, Mn（Ⅱ）, Fe（Ⅲ）, Ni（Ⅱ）, Zn（Ⅱ）, Hg（Ⅱ）, Co（Ⅱ）, Cu（Ⅱ）） by colorimetry and spectrofluorimetry has been explored. CPOH-AgNps were found to be selective only for Hg（Ⅱ） ions. Nanomolar concentration of Hg（Ⅱ） ions can also be determined by spectrofluorimetry by increase in fluorescence intensity. Linear range of detection of Hg（Ⅱ） ions in water was found to be from 1nmol/L to mol/L. The method has been successfully applied for determination of Hg（Ⅱ） ions in ground water and industrial effluent waste water samples.
