Probing the interaction of caffeic acid with ZnO nanoparticles |
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| Authors: | Abebe Belay Hyung Kook Kim Yoon‐Hwae Hwang |
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| Institution: | 1. Department of Nanomaterial Engineering & BK 21 Plus Nanoconvergence Technology Division, Pusan National University, Miryang, Korea;2. Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, Adama, Ethiopia |
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| Abstract: | The binding of ZnO nanoparticles (NPs) and caffeic acid (CFA) was investigated using fluorescence quenching, UV/vis absorption spectrscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) at different temperatures. The study results indicated fluorescence quenching between ZnO NPs and CFA rationalized in terms of a static quenching mechanism or the formation of non‐fluorescent CFA–ZnO. From fluorescence quenching spectral analysis, the binding constant (Ka), number of binding sites (n) and thermodynamic properties were determined. Values of the quenching (KSV) and binding (Ka) constants decrease with increasing temperature and the number of binding sites n = 2. The thermodynamic parameters determined using Van't Hoff equation indicated that binding occurs spontaneously involving the hydrogen bond, and van der Waal's forces played a major role in the reaction of ZnO NPs with CFA. The FTIR, TEM and DLS measurements also indicated differences in the structure, morphology and size of CFA, ZnO NPs and their corresponding CFA–ZnO. Copyright © 2015 John Wiley & Sons, Ltd. |
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| Keywords: | ZnO nanoparticles caffeic acid fluorescence quenching FTIR TEM DLS |
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