Fig. 6From: Colorimetric detection of Cr3+ based on gold nanoparticles functionalized with 4-mercaptobenzoic acidThe detection of Cr3+ using the modified AuNP. a The changing in the UV-vis spectra recorded for the 4-MBA modified AuNPs upon increasing of the Cr3+ concentration. b The relationship between A635nm/A520nm and the Cr3+ concentration, Inset: the linear calibration curveBack to article page