Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras
OPTICAL SENSOR FOR HEXAVALENT CHROMIUM
Technology Category/Market
Technology: Optical Sensor for heavy metal ions Industry: Healthcare, Food, Chemical, Manufacturing Leather, Mining. Applications: Drinking & wastewater quality monitoring, Blood testing, Environmental compliance and law enforcement agencies
Market: The global optical sensors market is projected at a CAGR of 6.33% during period of 2023-2028.
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Problem Statement
- In present era, Chromium is a widely used heavy metal, because of which hexavalent chromium ions are hazardous pollutants frequently found in natural resources water.
- Conventional techniques for Cr6+ detection & quantification by means of the standard methods using atomic absorption spectrometry or mass spectrometry are limited by requirement of expensive infrastructure & skilled personnel including other issues.
- Hence, there is a need to introduce present method which mitigate above challenges.
Technology
- Present invention discloses a method of fabricating a silica optical probe for Cr6+ detection.
- Further, said invention discussed an optical probe which comprises a U-bent silica optic fiber probe having a first end, a second end & a U-bent region, which is applicable for detecting Cr6+.
- Further, said optical probe includes a metal organic framework (MOF) called zeolite imidazole (ZIF-67) coated on an outer surface of the U-bent region shown in below figures.
- The method comprises a few steps explained in smart chart & Fig herein
- 1st Step explains about Fabricating a U-bent silica optic fiber probe
- 2nd Step explains about Activating an outer surface of the U-bent region to generate hydroxyl groups on the
- surface
- 3rd Step explains about Growing a metal organic framework (MOF) and Providing post-thermal treatment to the coated probe
- The invention describes about the chemical synthesis of ZIF-67, using 2-methyl imidazole & cobaltous nitrate hexahydrate shown in figures herein below.
- The aqueous solution of both chemicals is mixed in certain molarity & this freshly prepared growth mixture solution is used for the in-situ growth of thin films on U-bent silica optical fiber illustrates in figure.
Key Features/Value Proposition
Technical Perspective:
- ZIF-67 selectively entrap Cr6+ ions and the high EWA sensitivity of the U-FOS allows specific detection of Cr6+ ions by means of their intrinsic optical absorption around 395 nm.
- The MOF coated fiber probes are stable over a month even in humid and at room temperature.
- The claimed sensor demonstrates high selectivity for chromium ion detection with respect to other potential interfering heavy metal ions present in water such as Mn7+, Fe3+, Co2+, Cl– , Cu2+,Pb2+, Hg2+, Mg2+, Ca2+ , Ni2+, Cd2+, Zn2+, Li+.
- The proposed synthesis method is advantageous for many applications where fresh water may be used as medium for sensing.
Industrial Perspective:
- The ZIF-67 coated U-FOS Cr6+ sensor realized with a portable LED-photodetector set-up demonstrates a wide dynamic range & useful detection limits.
- Potentiality applicable to develop the U-FOS as a portable on-field sensor, or applicable to any other handheld device.
Questions about this Technology?
Contact for Licensing
Research Lab
Biosensors Lab-Prof. Raghavendra Sai V.V
Department of Applied Mechanics and Biomedical Engineering
Intellectual Property
- IITM IDF Ref.:2147
- Patent No. 202141023371
- PCT Application No. PCT/IN2022/050375
Technology Readiness Level
TRL-4/5
Proof of Concept ready, tested & validated