# US 11,442,032 B2 · Analysis of antimicrobial coatings using XRF > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,032 B2 - Document ID: US11442032B2 - Status: Granted - Kind: B2 - Application number: 17/234,330 - Filed: 2021-04-19 - Published: 2021-08-05 - Granted: 2022-09-13 - Earliest claimed: 2019-01-25 - Assignees: Srfc Bio, Inc. - Applicants: Allied Bioscience, Inc. - Inventors: Parham Asgari; Jie Fang; Gavri Grossman; Maha El-Sayed - Web page: https://patentgrep.com/patent/US11442032B2 ## CPC - G01N 23/223: by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence - G01B 15/02: for measuring thickness - G01N 2223/076: X-ray fluorescence - G01N 2223/1016: X-ray - G01N 2223/601: density profile - G01N 2223/61: thin films, coatings - G01N 2223/632: residual life, life expectancy - G01N 2223/633: thickness, density, surface weight (unit area) - 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) - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract A method of quantifying an antimicrobial coatings using a handheld XRF analyzer is disclosed. The method provides an estimate of the expected level of antimicrobial efficacy for a thin film comprising silicon and/or titanium by obtaining a 14Si or 22Ti peak intensity using XRF spectroscopy and converting the obtained 14Si or 22Ti peak intensity to the expected level of efficacy using a calibration curve. A properly calibrated handheld XRF analyzer allows a user to assess the viability of antimicrobial coatings in the field, such as in a hospital where various fomites may be coated with silane and/or titanium compositions. ## Claims ### Claim 1 A method of estimating an expected level of residual antimicrobial efficacy for an antimicrobial coating comprising an organosilane having a quaternary ammonium chloride substituent, the method comprising: obtaining 17Cl photon counts from the antimicrobial coating using XRF spectroscopy; and converting the obtained 17Cl photon counts to the expected level of residual antimicrobial efficacy using a calibration curve. ### Claim 2 (depends on 1) The method of claim 1, wherein the organosilane having a quaternary ammonium chloride substituent is selected from the group consisting of 3-(trimethoxysilyl) propyl dimethyl octadecyl ammonium chloride, 3-(trihydroxysilyl) propyl dimethyl octadecyl ammonium chloride, homopolymers therefrom, and mixtures thereof. ### Claim 3 (depends on 1) The method of claim 1, wherein the antimicrobial coating further comprises at least one of 3-chloropropyltrimethoxysilane, 3-thioropropyltriethoxysilane, 3-chloropropylsilanetriol, 3-aminopropyltrimethoxysilane, 3-aminopropyltdethoxysilane, or 3-aminopropylsilanetriol. ### Claim 4 (depends on 1) The method of claim 1, wherein the antimicrobial coating further comprises an organic amine. ### Claim 5 (depends on 1) The method of claim 1, wherein the step of obtaining the 17Cl photon counts comprises irradiation of the antimicrobial coating with X-rays emanating from a handheld XRF analyzer and detecting X-ray emissions from the coating. ### Claim 6 (depends on 1) The method of claim 1, wherein the calibration curve comprises an x/y plot of the expected level of residual antimicrobial efficacy for a desired microorganism versus the 17Cl photon counts. ### Claim 7 A method of measuring a thickness of an antimicrobial coating comprising an organosilane having a quaternary ammonium chloride substituent, the method comprising: obtaining initial 17Cl photon counts from the antimicrobial coating using XRF spectroscopy; subjecting the antimicrobial coating to mechanical abrasion; obtaining 17Cl photon counts from the antimicrobial coating after mechanical abrasion using XRF spectroscopy; and converting the obtained 17Cl photon counts to the thickness of the antimicrobial coating after mechanical abrasion using a calibration curve. ### Claim 8 (depends on 7) The method of claim 7, wherein the organosilane having a quaternary ammonium chloride substituent is selected from the group consisting of 3-(trimethoxysilyl) propyl dimethyl octadecyl ammonium chloride, 3-(trihydroxysilyl) propyl dimethyl octadecyl ammonium chloride, homopolymers therefrom, and mixtures thereof. ### Claim 9 (depends on 7) The method of claim 7, wherein the antimicrobial coating further comprises at least one of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-chloropropylsilanetriol, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or 3-aminopropylsilanetriol. ### Claim 10 (depends on 7) The method of claim 7, wherein the antimicrobial coating further comprises an organic amine. ### Claim 11 (depends on 7) The method of claim 7, wherein the step of obtaining the 17Cl photon counts comprises irradiation of the antimicrobial coating with X-rays emanating from a handheld XRF analyzer and detecting X-ray emissions from the coating. ### Claim 12 (depends on 7) The method of claim 7, wherein the calibration curve comprises an x/y plot of antimicrobial coating thickness versus 17Cl photon counts. ### Claim 13 A method of measuring a weight per unit of surface area of an antimicrobial coating comprising an organosilane having a quaternary ammonium chloride substituent, the method comprising: obtaining initial 17Cl photon counts from the antimicrobial coating using XRF spectroscopy; subjecting the antimicrobial coating to mechanical abrasion; obtaining 17Cl photon counts from the antimicrobial coating after mechanical abrasion using XRF spectroscopy; and converting the obtained 17Cl photon counts to the weight per unit of surface area of the antimicrobial coating after mechanical abrasion using a calibration curve. ### Claim 14 (depends on 13) The method of claim 13, wherein the organosilane having a quaternary ammonium chloride substituent is selected from the group consisting of 3-(trimethoxysilyl) propyl dimethyl octadecyl ammonium chloride, 3-(trihydroxysilyl) propyl dimethyl octadecyl ammonium chloride, homopolymers therefrom, and mixtures thereof. ### Claim 15 (depends on 13) The method of claim 13, wherein the antimicrobial coating further comprises at least one of 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-chloropropylsilanetriol, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or 3-aminopropylsilanetriol. ### Claim 16 (depends on 13) The method of claim 13, wherein the antimicrobial coating further comprises an organic amine. ### Claim 17 (depends on 13) The method of claim 13, wherein the step of obtaining the 17Cl photon counts comprises irradiation of the antimicrobial coating with X-rays emanating from a handheld XRF analyzer and detecting X-ray emissions from the coating. ### Claim 18 (depends on 13) The method of claim 13, wherein the calibration curve comprises an x/y plot of weight per unit of surface area of the antimicrobial coating versus 17Cl photon counts.