# US 9,846,127 B2 · Colorimetric detection sensor and colorimetric detection method for detecting cyanide anion by etching of gold nanorods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,846,127 B2 - Document ID: US9846127B2 - Status: Granted - Kind: B2 - Application number: 15/357,169 - Filed: 2016-11-21 - Published: 2017-06-08 - Granted: 2017-12-19 - Earliest claimed: 2015-12-02 - Assignees: Korea Institute of Science and Technology - Applicants: Korea Institute of Science and Technology - Inventors: Kangbong Lee; Yunsik Nam; Sujin Lee; Yeonhee Lee; Inhwan Oh - Web page: https://patentgrep.com/patent/US9846127B2 ## CPC - G01N 21/80: Indicating pH value - G01N 21/251: {Colorimeters; Construction thereof} - G01N 21/78: producing a change of colour - G01N 31/22: using chemical indicators (G01N31/02 takes precedence) - G01N 31/224: {for investigating presence of dangerous gases} - G01N 33/84: involving inorganic compounds or pH - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - G01N 27/12: of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid {, for detecting components in the fluid} - G01N 27/126: {comprising organic polymers} - G01N 33/4925: {measuring blood gas content, e.g. O2, CO2 , HCO3} - G01N 33/5014: {for testing toxicity} - G01N 33/5308: {for analytes not provided for elsewhere, e.g. nucleic acids, uric acid, worms, mites} - Y10T 436/172307: Cyanide or isocyanide - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Disclosed are a colorimetric detection sensor and colorimetric detection method of a cyanide anion (CN−) by etching of gold nanorods. The colorimetric detection sensor and colorimetric detection method use label-free nanorods having no modifier attached to a surface of gold nanorods (AuNRs), wherein the aspect ratio of nanorods, pH condition and/or amount of a surfactant are controlled to carry out selective etching and to cause a change in color only by CN− so that CN− contained or dissolved in poison, water-contaminated environmental samples and legal evidence samples may be detected with ease, and show excellent selectivity, sensitivity and quantitative analyzability to CN− to provide high usefulness. ## Claims ### Claim 1 A colorimetric detection sensor for detecting a cyanide anion (CN—), comprising a colorimetric sensor solution comprising gold nanorods having an aspect ratio of 0.29, wherein the gold nanorods are rod-shaped and are etched by CN— so that the rod-shaped gold nanorods are adapted to change into a spherical shape, and thereby are configured to produce a change in color due to a surface resonance phenomenon, and wherein the colorimetric sensor solution comprises cetyltrimethylammonium bromide (CTAB), which is a surfactant, at a concentration of 1-3 mM. ### Claim 2 (depends on 1) The colorimetric detection sensor according to claim 1, wherein the aspect ratio of the gold nanorods is 0.7-0.8. ### Claim 3 (depends on 1) The colorimetric detection sensor according to claim 1, wherein the gold nanorods have widths and lengths of 50 nm or less, respectively. ### Claim 4 (depends on 1) The colorimetric detection sensor according to claim 1, wherein the color of the colorimetric detection sensor changes from a blue color to a purple color, a pink color or transparency. ### Claim 5 (depends on 1) The colorimetric detection sensor according to claim 1, wherein the colorimetric detection sensor detects CN− in a range of pH 6-8. ### Claim 6 (depends on 1) The colorimetric detection sensor according to claim 1, wherein the colorimetric detection sensor detects CN− at pH 6. ### Claim 7 (depends on 1) The colorimetric detection sensor according to claim 1, wherein the colorimetric detection sensor detects CN− at a temperature ranging from room temperature to 50° C. ### Claim 8 (depends on 1) The colorimetric detection sensor according to claim 1, wherein a detection reaction of CN− is carried out within 30 minutes. ### Claim 9 (depends on 1) The colorimetric detection sensor according to claim 1, wherein a concentration of detected CN− is quantitatively determined by measuring a change in color of the colorimetric detection sensor with a spectrophotometer or colorimeter. ### Claim 10 (depends on 1) A colorimetric detection method for detecting CN−, which comprises: introducing a sample to be detected to a colorimetric detection sensor according to claim 1; and detecting 0.01 ppm or higher of CN− in the sample to be detected by a change in color of the colorimetric detection sensor, wherein the colorimetric detection sensor includes gold nanorods having an aspect ratio of 0.29-1. ### Claim 11 (depends on 10) The colorimetric detection method according to claim 10, which further comprises, before introducing the sample, adjusting pH and temperature of the colorimetric detection sensor to enhance stability and sensitivity of the nanorods. ### Claim 12 (depends on 10) The colorimetric detection method according to claim 10, wherein the colorimetric detection sensor shows color emission in a wavelength range of 450 nm-700 nm in the introducing, and shows color emission in a wavelength range of 500 nm-600 nm when CN− is present in the sample to be detected in the detecting. ### Claim 13 (depends on 10) The colorimetric detection method according to claim 10, wherein the colorimetric sensor has an absorbance ratio (A538/A679) of 0.5-10 in the detecting.