Colorimetric detection of Cr3+ using gold nanoparticles functionalized with 4-amino
hippuric acid
Weiwei Jin, Pengcheng Huang, Yueji Chen, Fang-Ying Wu, Yiqun Wan
Department of Chemistry, Nanchang University, Nanchang 330031, China
E-mail:fywu@ncu.edu.cn
Supplementary Material
List of Contents
page number
Fig. S1 IR spectra of pure PAH and PAH-AuNPs.
2
Fig. S2 Particle size distribution histogram of PAH-AuNPs.
2
Fig. S3 Analytical stability of the PAH-AuNPs toward Cr3+. Intensity ratio (A635nm/A520nm) of
PAH-AuNPs in the absence and presence of Cr3+ (A) for 10 days, and (B) for 5 batches.
3
Fig. S4 Intensity ratio of A635nm/A520nm in the presence of various concentrations PAH-AuNPs
against upon adding Cr3+.
3
Fig. S5 Effect of PAH concentration on the detection of Cr3+. UV-vis spectra of PAH-AuNPs as a
function of Cr3+ concentrations. Cr3+ concentrations increase from 0 to 120 μM with 5 μM as the
interval in the first 70 μM and 10 μM as the interval in the last 50 μM.
Fig. S6 Effects of pH on the detection of Cr3+. A635 nm/A520
nm
4
is the absorption ratio of the
detection Cr3+ in the absence and presence of Cr3+, respectively. Cr3+ Concentration: 50 µM.
Fig. S7 Effects of NaCl on the absorption ratio (A635nm/A520nm) of detection Cr3+
4
5
Fig. S8 Plots of the time-dependent absorption ratio (A635nm/A520nm) over 10 min in the presence of
varying concentrations of Cr3+.
5
Fig. S9 The plot of the the absorbance ratio (A635nm/A520nm) change of PAH-AuNPs upon addition
of increasing concentration of Cr3+ in the absence (black) and presence of 0.2 mM EDTA (red). 5
Fig. S10 Relationship between the absorbance ratio (A635nm/A520nm) of PAH-AuNPs and the
concentration of Cr3+ with deionized water (black), milk power (red), liquid milk (blue) and lake

Corresponding authors: Department of Chemistry, Nanchang University, Nanchang 330031, China, Tel: + 86 79183969882; Fax: + 86
79183969514. E-mail address: fywu@ncu.edu.cn.
1
water (green) samples.
6
Table S1 Cr3+ Detection methods published
6
Table S2 The Calibration equations in the different matrix.
7
Fig. S1 IR spectra of pure PAH and PAH-AuNPs.
Fig. S2 Particle size distribution histogram of PAH-AuNPs.
2
Fig. S3 Analytical stability of the PAH-AuNPs toward Cr3+. (A) Intensity ratio (A635nm/A520nm) of
PAH-AuNPs in the absence and presence of Cr3+ for 10 days, (B) Intensity ratio (A635nm/A520nm) of
PAH-AuNPs in the absence and presence of Cr3+ for 5 batches.
Fig. S4 Intensity ratio of A635nm/A520nm in the presence of various concentrations PAH-AuNPs
against upon adding Cr3+.
3
Fig. S5 Effect of PAH concentration on the detection of Cr3+. UV-vis spectra of PAH-AuNPs as a
function of Cr3+ concentrations. Cr3+ concentrations increase from 0 to 120 μM with 5 μM as the
interval in the first 70 μM and 10 μM as the interval in the last 50 μM.
Fig. S6 Effects of pH on the detection of Cr3+. A635 nm/A520
nm
is the absorption ratio of the
detection Cr3+ in the absence and presence of Cr3+, respectively. Cr3+ Concentration: 50 µM.
4
Fig. S7 Effects of NaCl on the absorption ratio (A635nm/A520nm) of detection Cr3+. A635nm/A520nm is
the absorption ratio of the detection Cr3+ in the absence and presence of Cr3+, respectively. Cr3+
Concentration: 50 µM.
Fig. S8 Plots of the time-dependent absorption ratio (A635nm/A520nm) over 10 min in the presence of
various concentrations of Cr3+.
Fig. S9 The plot of the absorbance ratio (A635nm/A520nm) change of PAH-AuNPs upon addition of
5
increasing concentration of Cr3+ in the absence (black) and presence of 0.2 mM EDTA (red).
Fig. S10 Relationship between the absorbance ratio (A635nm/A520nm) of PAH-AuNPs and the
concentration of Cr3+ with deionized water (black), milk power (red), liquid milk (blue) and lake
water (green) samples.
Table S1 Cr3+ Detection Methods Published
Method
Colorimetric detection of Cr3+
using tripolyphosphate modified
gold nanoparticles
Xanthoceras
sorbifoliatannin
attached to gold nanoparticles
Colorimetric
speciation
of
Cr(III) and Cr(VI) with a gold
nanoparticle probe
Selective detection of Cr(III) in
aqueous solution based on a gold
nanoparticles
Immunochromatographic assay
for the rapid detection of
chromium ions
Fluorescent turn-on chemosensor
for Fe3+ and Cr3+
Sensitive and selective SERS
probe for trivalent chromium
Fluorescence quenching method
for determination Cr3+ based on
Linearity
range
LOD
μM
Response
to ions
Ref.
0.22-22μM
0.10
Cr3+
1
10-100 μM
3.0
Cr3+
2
2-8μM
0.30
Cr3+ Cr6+
3
0-0.4μM
0.4-0.8μM
0.12
Cr3+
4
5–80 ng mL−1
0.018
Cr3+ Cr6+
5
NA
2.57
Fe3+ Cr3
6
0-200 nM
0.05
Cr3+
7
0.1-20μM
0.03
Cr3+
8
6
CdSe QDs
PAH modified AuNPs
5-120μM
1.17
Cr3+
This
way
1. Xin, J.; Miao, L.; Chen, S.; Wu, A., Colorimetric detection of Cr3+ using tripolyphosphate
modified gold nanoparticles in aqueous solutions. Anal. Methods 2012, 4, 1259-1264.
2. Ha, W.; Yu, J.; Wang, R.; Chen, J.; Shi, Y.-p., “Green” colorimetric assay for the selective
detection of trivalent chromium based on Xanthoceras sorbifolia tannin attached to gold
nanoparticles. Anal. Methods. 2014, 6, 5720-5726.
3. Liu, Y.; Wang, X., Colorimetric speciation of Cr(III) and Cr(VI) with a gold nanoparticle probe.
Anal. Methods. 2013, 5, 1442-1448.
4. Zhao, L.; Jin, Y.; Yan, Z.; Liu, Y.; Zhu, H., Novel, highly selective detection of Cr(III) in
aqueous solution based on a gold nanoparticles colorimetric assay and its application for
determining Cr(VI). Anal. Chim. Acta 2012, 731, 75-81.
5. Liu, X.; Xiang, J.-J.; Tang, Y.; Zhang, X.-L.; Fu, Q.-Q.; Zou, J.-H.; Lin, Y., Colloidal gold
nanoparticle probe-based immunochromatographic assay for the rapid detection of chromium ions
in water and serum samples. Anal. Chim. Acta 2012, 745, 99-105.
6. Zhu, W.; Yang, L.; Fang, M.; Wu, Z.; Zhang, Q.; Yin, F.; Huang, Q.; Li, C., New
carbazole-based Schiff base: Colorimetric chemosensor for Fe3+ and fluorescent turn-on
chemosensor for Fe3+ and Cr3+. J. Lumin. 2015, 158, 38-43.
7. Ye, Y.; Liu, H.; Yang, L.; Liu, J., Sensitive and selective SERS probe for trivalent chromium
detection using citrate attached gold nanoparticles. Nanoscale. 2012, 4, 6442-6448.
8. Sung, T.-W.; Lo, Y.-L.; Chang, I. L., Highly sensitive and selective fluorescence probe for Cr3+
ion detection using water-soluble CdSe QDs. Sensors and Actuators B: Chemical 2014, 202,
1349-1356.
Table S2 The calibration equations in the different matrix
Material
Calibration equation
Correlation coefficient (r)
Deionized water
y=0.00925 [C]/µM + 0.161
0.998
Milk power
y=0.00943 [C]/µM + 0.161
0.999
Liquid milk
y=0.0100 [C]/µM + 0.153
0.998
Lake water
y=0.0102 [C]/µM + 0.139
0.999
7