Gold nanoparticles (GNPs) have been widely used in diagnostic, tissue engineering, and drug delivery fields, in the last decades. Generally, reducing gold salts to zero valent gold has been accomplished by harsh chemicals and strong reducing agents, which cause toxicity and eventually limiting the bioapplications. Green synthesis is a newly developing methodology to synthesize GNPs. Especially natural products and plants extracts are commonly preferred for green synthesis based on their natural content. Biological molecule-capped GNPs, are more biofriendly and biocompatible nano-materials that can be used for varied applications.1-3 Sensor applications; varying from biosensing to environmental analysis, are an important field that GNPs were intensively utilized.4-5 Cyanide ion (CN-) has been considered as one of the main pollutants of water, because of its rapid discharge. CN- is currently being used in industry such as; polymer synthesis6, noble metal mining7, pest control8, plastics production etc., at large scale. However, there is an unmet need for CN- detection and monitoring. Colorimetric detection of CN- that utilizes GNPs has been done by several researchers.9-10 However, in all these studies reduction of GNPs were done by strong reducing agents. Green synthesis of GNPs eliminates the toxic side-products that can be harmful to both environment and human health. To overcome this problem green synthesized GNPs were used to establish the sensor platform, which can be further employed for CN- detection. Oxidation of GNPs in the presence of cyanide molecules is a direct-forward, colorimetric and optical method that requires no toxic chemicals; therefore it is a greener approach towards CN- detection in water resources.