TY - JOUR
T1 - Surface-enhanced Raman scattering of perchlorate on cationic-modified silver nanofilms - Effect of inorganic anions
AU - Hao, Jumin
AU - Han, Mei Juan
AU - Meng, Xiaoguang
AU - Weimer, Wayne
AU - Wang, Qingwu K.
N1 - Publisher Copyright:
© 2014 Elsevier B.V. All rights reserved.
PY - 2015/2/5
Y1 - 2015/2/5
N2 - (Graph Presented). Surface-enhanced Raman scattering (SERS) has emerged as one of the most sensitive spectroscopic analysis methods for the detection of environmental contaminants in water, including perchlorate (ClO4-). However, as with other commonly used analytical techniques, analysis of realistic environmental samples by SERS presents a challenge due to complex chemical components coexisting in the samples. In this work, we investigated the influence of inorganic anions (particularly oxyanions) on SERS spectra of ClO4- using a cationic thiol modified silver nanofilm substrate (Cys-Ag/rCu). The results show that the anions present in the samples did not shift the ClO4- characteristic band positions, but did decrease signal intensities due to their competitive binding with the -NH3+ groups of cationic thiol molecules immobilized on the substrates. The pH changes caused by both the dissociation of H2PO4- and the hydrolysis of HCO3- may also play a non-negligible role. The selectivity of the Cys-Ag/rCu substrate towards these anions was determined to be in the following order: ClO4- > SO42- > HCO3-, NO3- > Cl- > H2PO4-, indicating preferential ions. In the solutions with multiple anions present, the ClO4- adsorption of ClO4- SERS spectra were affected simultaneously by all the coexisting anions. Calibration curves with very good linear relationships were successfully obtained, demonstrating the great potential of quantitative detection of aqueous in the matrix.
AB - (Graph Presented). Surface-enhanced Raman scattering (SERS) has emerged as one of the most sensitive spectroscopic analysis methods for the detection of environmental contaminants in water, including perchlorate (ClO4-). However, as with other commonly used analytical techniques, analysis of realistic environmental samples by SERS presents a challenge due to complex chemical components coexisting in the samples. In this work, we investigated the influence of inorganic anions (particularly oxyanions) on SERS spectra of ClO4- using a cationic thiol modified silver nanofilm substrate (Cys-Ag/rCu). The results show that the anions present in the samples did not shift the ClO4- characteristic band positions, but did decrease signal intensities due to their competitive binding with the -NH3+ groups of cationic thiol molecules immobilized on the substrates. The pH changes caused by both the dissociation of H2PO4- and the hydrolysis of HCO3- may also play a non-negligible role. The selectivity of the Cys-Ag/rCu substrate towards these anions was determined to be in the following order: ClO4- > SO42- > HCO3-, NO3- > Cl- > H2PO4-, indicating preferential ions. In the solutions with multiple anions present, the ClO4- adsorption of ClO4- SERS spectra were affected simultaneously by all the coexisting anions. Calibration curves with very good linear relationships were successfully obtained, demonstrating the great potential of quantitative detection of aqueous in the matrix.
KW - Cationic thiol
KW - Competitive adsorption
KW - Inorganic anions
KW - Perchlorate detection
KW - Silver nanofilm
KW - Surface-enhanced raman scattering (SERS)
UR - http://www.scopus.com/inward/record.url?scp=84912077813&partnerID=8YFLogxK
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U2 - 10.1016/j.saa.2014.10.052
DO - 10.1016/j.saa.2014.10.052
M3 - Article
AN - SCOPUS:84912077813
SN - 1386-1425
VL - 136
SP - 1593
EP - 1599
JO - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
JF - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
IS - PC
ER -