One-pot biosynthesis of silver nanoparticle using Colocasia esculenta extract: Colorimetric detection of melamine in biological samples

Here we report an eco-friendly and robust silver nanoparticles (AgNPs) as a simple and sensitive probe for the detection of melamine in biological samples. The AgNPs were synthesized using the extract of Colocasia esculenta. The spherical shaped and monodispersed AgNPs were obtained with an average particle size of 20 nm. The as synthesized colorimetric probe was morphologically and spectroscopically characterized using transmission electron microscope and fourier-transform infrared and UV-vis spectrometry respectively. This method is based on the melamine induced aggregation of AgNPs, hence, color changes from yellow to orange red. Various experimental parameters such as effect of pH and time on the detection of melamine was investigated to enhance the sensitivity of the developed method. Under optimized conditions, the limit of detection and limit of quantification were found to be 0.070 ppm and 1.60 ppm respectively with a recovery values ranging from 95.0-103%. The findings of this study resulted in the development of highly sensitive and selective sensing probe for the detection of melamine in biological samples.