Simple preparation of positively charged silver nanoparticles for detection of anions by surface-enhanced Raman spectroscopy

A. Stewart, S. Murray, S. E. J. Bell*

*Corresponding author for this work

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Modification of citrate and hydroxylamine reduced Ag colloids with thiocholine bromide, a thiol functionalized quaternary ammonium salt, creates particles where the zeta potential is switched from the normal values of ca. -50 mV to ca. + 50 mV. These colloids are stable but can be aggregated with metal salts in much the same way as the parent colloids. They are excellent SERS substrates for detection of anionic targets since their positive zeta potentials promote adsorption of negatively charged ions. This is important because the vast majority of published SERS studies involve cationic or neutral targets. Moreover, the fact that the modifier is a quaternary ammonium ion means that the negative surface charge is maintained even at alkaline pH. The modified colloids can be used to detect compounds which cannot be detected using conventional negatively-charged citrate or hydroxylamine reduced metal nanoparticles, for example the detection limit was 5.0 x 10(-5) M for perchlorate and

Original languageEnglish
Pages (from-to)2988-2994
Number of pages7
JournalAnalyst
Volume140
Issue number9
DOIs
Publication statusPublished - 2015

Keywords

  • PERCHLORATE DETECTION
  • SCATTERING
  • SERS
  • MONOLAYERS
  • COLLOIDS
  • NITRATE
  • ACID

Cite this

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title = "Simple preparation of positively charged silver nanoparticles for detection of anions by surface-enhanced Raman spectroscopy",
abstract = "Modification of citrate and hydroxylamine reduced Ag colloids with thiocholine bromide, a thiol functionalized quaternary ammonium salt, creates particles where the zeta potential is switched from the normal values of ca. -50 mV to ca. + 50 mV. These colloids are stable but can be aggregated with metal salts in much the same way as the parent colloids. They are excellent SERS substrates for detection of anionic targets since their positive zeta potentials promote adsorption of negatively charged ions. This is important because the vast majority of published SERS studies involve cationic or neutral targets. Moreover, the fact that the modifier is a quaternary ammonium ion means that the negative surface charge is maintained even at alkaline pH. The modified colloids can be used to detect compounds which cannot be detected using conventional negatively-charged citrate or hydroxylamine reduced metal nanoparticles, for example the detection limit was 5.0 x 10(-5) M for perchlorate and",
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Simple preparation of positively charged silver nanoparticles for detection of anions by surface-enhanced Raman spectroscopy. / Stewart, A.; Murray, S.; Bell, S. E. J.

In: Analyst, Vol. 140, No. 9, 2015, p. 2988-2994.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Simple preparation of positively charged silver nanoparticles for detection of anions by surface-enhanced Raman spectroscopy

AU - Stewart, A.

AU - Murray, S.

AU - Bell, S. E. J.

PY - 2015

Y1 - 2015

N2 - Modification of citrate and hydroxylamine reduced Ag colloids with thiocholine bromide, a thiol functionalized quaternary ammonium salt, creates particles where the zeta potential is switched from the normal values of ca. -50 mV to ca. + 50 mV. These colloids are stable but can be aggregated with metal salts in much the same way as the parent colloids. They are excellent SERS substrates for detection of anionic targets since their positive zeta potentials promote adsorption of negatively charged ions. This is important because the vast majority of published SERS studies involve cationic or neutral targets. Moreover, the fact that the modifier is a quaternary ammonium ion means that the negative surface charge is maintained even at alkaline pH. The modified colloids can be used to detect compounds which cannot be detected using conventional negatively-charged citrate or hydroxylamine reduced metal nanoparticles, for example the detection limit was 5.0 x 10(-5) M for perchlorate and

AB - Modification of citrate and hydroxylamine reduced Ag colloids with thiocholine bromide, a thiol functionalized quaternary ammonium salt, creates particles where the zeta potential is switched from the normal values of ca. -50 mV to ca. + 50 mV. These colloids are stable but can be aggregated with metal salts in much the same way as the parent colloids. They are excellent SERS substrates for detection of anionic targets since their positive zeta potentials promote adsorption of negatively charged ions. This is important because the vast majority of published SERS studies involve cationic or neutral targets. Moreover, the fact that the modifier is a quaternary ammonium ion means that the negative surface charge is maintained even at alkaline pH. The modified colloids can be used to detect compounds which cannot be detected using conventional negatively-charged citrate or hydroxylamine reduced metal nanoparticles, for example the detection limit was 5.0 x 10(-5) M for perchlorate and

KW - PERCHLORATE DETECTION

KW - SCATTERING

KW - SERS

KW - MONOLAYERS

KW - COLLOIDS

KW - NITRATE

KW - ACID

U2 - 10.1039/c4an02305f

DO - 10.1039/c4an02305f

M3 - Article

VL - 140

SP - 2988

EP - 2994

JO - The Analyst

JF - The Analyst

SN - 0003-2654

IS - 9

ER -