Effective colorimetric detection of Ni2+ using gold nanoparticles functionalized with phytate

A colorimetric sensor for detection of Ni 2+ with high sensitivity and selectivity has been developed by functionalizing gold nanoparticles (AuNPs) with phytate (PA) in aqueous solution. The as-prepared PA-AuNPs exhibit the excellent selectivity for colorimetric detection of Ni 2+ over 13 metal ions in 15 min. In the presence of Ni 2+ , the color of PA-AuNPs changes from red to blue, and the plasmon absorption exhibits a redshift. The detection limit of PA-AuNPs is found to be 5 μM and 0.216 μM for naked eyes and UV–vis spectroscopy on basis of signal-to-ratio of 3:1 respectively.