Highly sensitive and selective colorimetric detection of arginine by polyvinylpyrrolidone functionalized silver nanoparticles

The present study reported on the qualitative and quantitative detection of arginine by using silver nanoparticle (Ag NPs) from aqueous sample. Ag NPs conjugated with arginine reacts with the Pb2+ forms a complex which changes the brownish yellow colour to black colour. The prepared particle was characterized by UV–visible spectrophotometer, scanning electron microscopy (SEM), particle size analyzer and zeta sizer. The maximum absorption of synthesized nanoparticle was observed at 412 nm. The diameter of prepared particle was measured by using particle size analyzer and it was found to be 7 ± 1.2 nm. The surface charge of the Polyvinylpyrrolidone (PVP) stabilized Ag NPs was −32.96 ± 3 mV. The UV–visible absorption spectra showed double peak at 392 nm and 576 nm indicates the formation of complex of Pb2+ with Ag NPs-arginine conjugate. The limit of detection of arginine of the present study was found to be 0.1 nM. The different environmental conditions (temperature, pH and salinity) were studied on arginine detection. There was no interference of other amino acid on the detection of arginine. The present study can be used as a highly selective and sensitive colorimetric method for the quantification of arginine from various aqueous media.