Carbon dots (C. dots) are the latest member of the carbon nanomaterial family. They are zero-dimensional carbon nanoparticles with size below 10 nm. They have gained intensive attention from the research community due to their remarkable properties like excellent fluorescence, good biocompatibility, high photostability and other electronic and chemical properties. All these attributes aided them in a number of applications in various fields such as optical sensing, bioimaging, photovoltaic devices, catalysis and drug delivery applications. In this article the C. dots obtained from Sunflower seeds are used as reducing agent for the conversion of Ag(I)to AgNPs. This C. dots- AgNPs are then used for the detection of Cysteine (Cys) and the limit of detection is found to be 6.31μM