Spectrophotometric and colorimetric determination of gallium (III) with p-aminohippuric acid-functionalized citrate capped gold nanoparticles

A new technique for sensing Ga(III) concentration based on polyvinyl alcohol-citrate capped gold nanoparticle–p-aminohippuric acid hybrid (or three-layer core-shell configurations) has been demonstrated. The p-aminohippuric acid capped citrate-gold nanoparticles were comfortably agglomerated in the presence of Ga(III), and the color of the reaction quickly turned from red to violet or blue. Under the detection conditions, a good linear relationship was ideally obtained between the ratio of the absorbance intensity at 620 nm to that at 520 nm (A620/A520). The linear response range, the detection, and quantification limit was 34.9–418.3 μg/L and 7.6 μg/L, and 25 μg/L, respectively