Green Synthesis Of Silver Nanoparticles Using N-Acetyl- L -Cysteine For Colorimetric Detection Of Methamphetamine

Abstract

Methamphetamine (METH) addiction has become a serious public health problem, worldwide. In this study, an alternative eco-friendly method for the synthesis of silver nanoparticles (AgNPs) using N-acetyl-L-cysteine (NAC) as a reducing and stabilizing agent was proposed. The biosynthesized AgNPs were conjugated with a specific aptamer to develop a label-free colorimetric sensor for the highly sensitive and selective quantification of METH. The prepared nanoparticles were characterized using UV-Vis, FTIR, XRD, TEM, FE-SEM, EDX, DLS and Zeta potential measurements. The results indicated that silver nanoparticles were successfully prepared (15-25 nm), and they were stable and homogeneous. The colorimetric sensing platform showed with the naked eye a color change upon detection of METH, which was caused by the aggregation of the nanoparticles induced by aptamer-target binding offering a visual and spectrophotometric read-out. The biosensor presented in this work provides an inexpensive, rapid and non-invasive method for determining the presence of methamphetamine. Thus, the outcomes of this study can be vastly utilized in forensic and clinical applications.