摘要： In recent work, we demonstrate a rapid colorimetric and easy visual determination of cyanide ions (CNˉ ions) in water based on gold nanoparticles stabilized with β-cyclodextrin (β-CD). Optical detection of CNˉ ions were carried out using β-CD-AuNPs by tracking the changes in the SPR band and colorimetric nature of the β-CD AuNPs. This colorimetric nanosensor capably and ultra sensitively distinguishes the CNˉ ions owing to the capacity of etching the β-CD AuNPs surface and form a stable water soluble Au-CN complex. Under investigational conditions, the colorimetric assay demonstrated a steady response for CNˉ ions over a concentration arrays from 4.50 × 10-6 to 99.00 × 10-6 mol dm-3 with R = 0.994. Lowest limit of detection of this economical, naked eye visual approach is 93.00 × 10-9 mol dm-3, which is under the tolerant limit value (1.90 × 10-6 mol dm-3) described by the World health organization in drinking water. Specificity of β-CD-AuNPs based optical platform for the detection of CNˉ ions is superb evaluated with the various potential interfering anions. Furthermore, the proposed β-CD-AuNPs nanoprobe is effectively applied to quantify the CNˉ ions in tap and drinking water samples. For convenient use, we have designed a very stable β-CD-AuNPs containing cotton swab and it revealed good sensitivity against CNˉ ions in the environment with only bare eye.