A dithiothreitol-modified nanogold resonance Rayleigh scattering spectral probe for detection of trace Cr(VI)

摘要

Nanogold (NG) in size of 15 nm was prepared by sodium citrate procedure, and it was modified by 1,4-dithiothreitol (DTT) to form NG-DTT probe for Cr(VI). In diluted H_2SO_4 medium, the probe interacted with Cr(VI) to form big NG clusters that led to the resonance Rayleigh scattering (RS) peak at 720 nm increased greatly. Under the selected conditions, the increased RS intensity (ΔI_(720nm)) is linear to Cr(VI) concentration in the range of 10-50 nmol/L, with a regression equation of ΔI_(720nm)= 2.05 C-7.5, coefficient of 0.9989, and a detection limit of 5 nmol/L. This nanogold RS method was applied to determination of Cr(VI) in waste water samples, with satisfactory results.