naa a22 4500 510816118 CHVBK 20180411083508.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11468-013-9559-1 doi (NATIONALLICENCE)springer-10.1007/s11468-013-9559-1 Surface Plasmon Tunability and Emission Sensitivity of Ultrasmall Fluorescent Copper Nanoclusters [Elektronische Daten] [Sujit Ghosh, Dewan Rahman, Abdul Ali, Anamika Kalita] Ultrasmall copper nanoparticles have been synthesized using copper(II) salt as precursor by hydrazine reduction in the presence of citric acid and cetyltrimethylammonium bromide facilitating the growth of stable copper nanoparticles with an average diameter of <2nm. The corresponding surface plasmon resonances were monitored under variable microenvironments, and it is seen that these tiny copper nanoparticles form aggregates under stipulated reaction conditions. It is noted that ultrasmall copper nanoparticles do not exhibit any characteristic surface plasmon band in the visible region; rather, a continuous absorption is seen over the entire UV-vis region. However, a well-defined plasmon absorption band makes its appearance while the particles are aggregated in close-packed assembly. These results demonstrate that the maximum of surface plasmon resonance is red-shifted from that of isolated particles because of electromagnetic interaction between the particles. The aggregation process is manifested upon changes of pH, anionic surfactant, etc. and is not reversible, i.e., the aggregates could not be re-dispersed into ultrasmall particles. The effect of addition of electrolyte has been monitored to study the surface plasmon damping of the copper nanoparticles. The plasmonic sensitivity of the copper nanoparticle aggregates has been elicited by the determination of amino acid chain length with exquisite sensitivity because of enormous electromagnetic field at the junction of the particles in the aggregates. Interestingly, the as-synthesized ultrasmall copper nanoclusters exhibit excellent fluorescence properties with a narrow emission profile. The emission properties of these copper nanoclusters have been utilized as an indicator for selective and ultrasensitive detection of highly toxic HgII ions in water in the nanomolar detection limit. Springer Science+Business Media New York, 2013 Copper nanoparticles nationallicence Surface plasmon resonance nationallicence Nanoscale aggregation nationallicence Electromagnetic interaction nationallicence Sensing nationallicence Ghosh Sujit Department of Chemistry, Assam University, 788011, Silchar, India aut Rahman Dewan Department of Chemistry, Assam University, 788011, Silchar, India aut Ali Abdul Department of Chemistry, Assam University, 788011, Silchar, India aut Kalita Anamika Department of Chemistry, Assam University, 788011, Silchar, India aut Plasmonics Springer US; http://www.springer-ny.com 8/3(2013-09-01), 1457-1468 1557-1955 8:3<1457 2013 8 11468 https://doi.org/10.1007/s11468-013-9559-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11468-013-9559-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ghosh Sujit Department of Chemistry, Assam University, 788011, Silchar, India aut NATIONALLICENCE 700 1- Rahman Dewan Department of Chemistry, Assam University, 788011, Silchar, India aut NATIONALLICENCE 700 1- Ali Abdul Department of Chemistry, Assam University, 788011, Silchar, India aut NATIONALLICENCE 700 1- Kalita Anamika Department of Chemistry, Assam University, 788011, Silchar, India aut NATIONALLICENCE 773 0- Plasmonics Springer US; http://www.springer-ny.com 8/3(2013-09-01), 1457-1468 1557-1955 8:3<1457 2013 8 11468 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer