Figure A. Photographs of the heated mixture and the aqueous colloidal solution at
different growth time.
a:
The deep green film formed on the inner wall of the glass bottle by heating the
HAuCl4-doped sugar mixture at 80 ℃ for 15 min.
b:
The orange-yellow solution obtained within 1 min after dissolving the heated
mixture in deionized water at room temperature.
c:
The solution kept 30 min after dissolution (without stirring).
d:
The solution kept 50 min after dissolution (without stirring). The solution appeared
dark red due to a high concentration of Au nanoparticles.
Intensity (a. u.)
60
40
20
0
30
40
50
60
2Theta (deg)
70
80
Figure B. XRD pattern of the solid mixture of H2AuCl4 and sucrose heated at 80 ℃
for 15 min. The pattern was obtained using a MAC diffractometer at 40 kV and 40 mA
and at λ = 1.54 Å (Cu Kα irradiation).
1.2
Absorbance
0.9
0.6
0.3
0
400
450
500
550
600
650
700
750
800
Wavelength (nm)
Figure C. Surface plasmon absorption spectrum of gold nanoparticles in aqueous
solution prepared by first heating the solid mixture of starch and HAuCl4 at 100 ℃ for
2 h and then dissolving the mixture in deionized water.
Figure D. TEM image of gold nanoparticles of ∼ 5nm diameter prepared using as raw
material.