Display omitted •A novel method for biosynthesized silver nanoparticles based on bitter orange bloom extract was presented.•AgNPs was subsequently utilized to detect and determine cyanide ions.•The developed colorimetric sensor can detect cyanide ions with good selectivity in aqueous solutions. Developing new methods for detecting and determining toxic anions is an essential parameter from waste sources for industrial and environmental scientists. This study presented, a new process for the biosynthesis of silver nanoparticles (AgNPs) based on the bitter orange bloom extract and its potential as a highly selective and sensitive chemosensor for detecting and quantifying cyanide ions. These biosynthesized AgNPs have a sharp and intense surface plasmon resonance (SPR) peak around 405 nm. AgNPs with a yellow color can be changed to colorless in the presence of a certain concentration of cyanide ions due to forming a new adduct between AgNPs and cyanide ions. Hence, the SPR intensity of AgNPs decreases, and the color of the solution becomes colorless. The sensor response to cyanide ions was linear in the concentration range of 49.7 to 1208.8 nM, and the detection limit was equal to 7.9 nM. As an applicable alternative, this assay is highly capable of qualitative and quantitative measurements of cyanide ions in the waste and toxic samples.