Silver Nanoparticle-Enhanced Resonance Raman Sensor of Chromium(III) in Seawater Samples

Sensors

Nguyễn Hoàng Ly²  Sang-Woo Joo¹ 

[1] Department of Chemistry, Soongsil University,Seoul 156-743, Korea; E-Mail

关键词: Cr(III);    EDTA;    Raman spectroscopy;    silver nanoparticles;    seawater;   

DOI  :  10.3390/s150510088

来源: mdpi

【 摘 要 】

Tris(hydroxymethyl)aminomethane ethylenediaminetetraacetic acid (Tris-EDTA), upon binding Cr(III) in aqueous solutions at pH 8.0 on silver nanoparticles (AgNPs), was found to provide a sensitive and selective Raman marker band at ~563 cm⁻¹, which can be ascribed to the metal-N band. UV-Vis absorption spectra also supported the aggregation and structural change of EDTA upon binding Cr(III). Only for Cr(III) concentrations above 500 nM, the band at ~563 cm⁻¹ become strongly intensified in the surface-enhanced Raman scattering spectra. This band, due to the metal-EDTA complex, was not observed in the case of 50 μM of K⁺, Cd²⁺, Mg²⁺, Ca²⁺, Mn²⁺, Co²⁺, Na⁺, Cu²⁺, NH₄⁺, Hg²⁺, Ni²⁺, Fe³⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions. Seawater samples containing K, Mg, Ca, and Na ion concentrations higher than 8 mM also showed the characteristic Raman band at ~563 cm⁻¹ above 500 nM, validating our method. Our approach may be useful in detecting real water samples by means of AgNPs and Raman spectroscopy.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.