UV-vis absorption spectra of the reduction of 4-nitrophenol in the presence of AuNPs. UV-visible absorption spectra of (a) 4-nitrophenol and (b) successive UV-vis absorption spectra (1-min interval) of the reduction of 4-nitrophenol by NaBH4 in the presence of AuNPs prepared at 4°C. The inset shows the corresponding plasmon band intensity of AuNPs around 530 nm.
Premkumar et al. Nanoscale Research Letters 2011 6:547 doi:10.1186/1556-276X-6-547