Selective aggregation of polyanion-coated gold nanorods induced by divalent metal ions in an aqueous solution.
A simple, accurate method for detecting metal ions in an aqueous solution using functionalized gold nanorods (AuNRs) is described. The method involves the complexing of divalent metal ions with poly(acrylic acid) (PAA) and, the localized surface plasmon resonance (LSPR) phenomena of AuNRs. Changes in the longitudinal surface plasmon bands (LSPBs) were monitored using aggregates of PAA-coated AuNRs with various divalent metal ions via UV-vis spectroscope. Functionalized AuNRs underwent robust aggregate formation by chelation with divalent metal ions (e.g., Cu2+, Zn2+, Cd2+, and Fe2+). Copper ions formed largest aggregates within 2 h, because complexation between Cu2+ and dicarboxylate has the highest deltaH and -deltaG values. This process represents an easy and useful method for detecting certain divalent metal ions, and the aggregates are also, in some cases, clearly visible to the naked eye.
Yang
Young In
YI
School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 151-742 Seoul, Korea.
Choi
Inhee
I
Hong
Surin
S
Lee
Suseung
S
Kang
Taewook
T
Lee
Hyunjoo
H
Yil
Jongheop
J