Functionalized Silver Nanoparticles for Rapid Detection of Mn2+ Employing a Smartphone Platform

Abstract

This study describes the development of a simple, reliable, and low-cost method to rapidly detect Mn2+ based on co-functionalized silver nanoparticles (AgNPs) and the smartphone platform to be applied as an on-site device in the field. The co-functionalized AgNPs was investigated with other cations (Al3+, Ba2+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Fe2+, Fe3+, K+, Li+, Mg2+, Na+, Ni2+, Pb2+ and Zn2+) at pH 3–10. The results showed that this functionalized AgNPs was selectively binded to Mn2+ at pH 10, which caused the color of the solution changing from yellow to orange-red and can be measured by the smartphone application called PhotoMetrix. This application was used to measure color intensities based on RGB (red, green, blue) values and converted into Mn2+ concentration by using multivariate calibration curves within 10 minutes. The smartphone detection showed a high selectivity of AgNPs with Mn2+ and provided a positive coefficient correlation between the intensity of channel R and the concentration of Mn2+ with a linear range of 4.0×10−5–2.0×10−4 M (R2=0.9814) and a limit of detection of 2.7×10−5 M. Furthermore, the quantification of Mn2+ in real water samples can be successfully applied by this method. The obtained results were in close agreement with those obtained with inductively coupled plasma optical emission spectroscopy (ICP-OES). Therefore, the development of a colorimetric system based on a smartphone system device was found to be feasible and reliable for on-site Mn2+ detection in the real water samples. © 2023 Wiley-VCH GmbH.