Supporting Information
Trichloroacetic acid assisted synthesis of gold nanoparticles and its application in detection and estimation of pesticide
Gadadhar Barman, Swarnali Maiti and J. Konar*
Department of Chemistry, Midnapore College, Midnapore-721101, W.B, India
Corresponding author. Tel.: +91 9434029182
E-mail address: (J.Konar)
Fax: +91 3222275847
Supporting Information
The change of concentrations of CTAB and chlroauric acid (Figure S1A and S1B) show that with the increase of concentrations from 10 -3 (M) to 5×10-3(M) increase the absorbance of 532 nm peak considerably but at pH 9.5, where we get the most stable sol, both the concentrations were kept at 3×10-3(M).
Fig. S1 UV-Vis spectra of GNP formation with varying concentrations of (A) chloroauric acid (B) CTAB.
The time of reaction was varied from 20 minutes to 2 hours and it was found that absorbance of the GNP peak increases with the increase of the time but the optimum time was found to be 1 hour when we get the most stable sol at 850C at pH 9.5 (Figure S2A). A blank test with pure chloroauric acid and methyl parathion shows no peak at 400 nm which justifies the formation of Au-S co-ordination bond between GNP with methyl parathion but not with Au (III). (Figure S2B).
Fig. S2 UV-Vis spectra of GNP formation varying time of reaction from 20 minutes to 2 hours keeping chloroauric acid concentration constant at 3×10 -3 (M) and (B) Absorption spectra of pure chloroauric acid in presence of methyl parathion at various concentration.
Fig. S3 Different TEM micrographs of GNP (A) & (B) and GNP after reaction with methyl parathion (C) & (D).
Fig. S4 UV representation of aggregation of GNP (A) due to reaction with methyl parathion (B) and segregation of GNP by reduction with NaBH4 (C).
Figure S5. FTIR spectra of (A) GNP and (B) GNP with methyl parathion.
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