Researchers Report Invention of Glucose-Sensing Contact Lens
October 6, 2016 | University of HoustonEstimated reading time: 2 minutes
Blood testing is the standard option for checking glucose levels, but a new technology could allow non-invasive testing via a contact lens that samples glucose levels in tears.
“There’s no noninvasive method to do this,” said Wei-Chuan Shih, a researcher with the University of Houston who worked with colleagues at UH and in Korea to develop the project, described in the high-impact journal Advanced Materials. “It always requires a blood draw. This is unfortunately the state of the art.”
But glucose is a good target for optical sensing, and especially for what is known as surface-enhanced Raman scattering spectroscopy, said Shih, an associate professor of electrical and computer engineering whose lab, the NanoBioPhotonics Group, works on optical biosensing enabled by nanoplasmonics.
This is an alternative approach, in contrast to a Raman spectroscopy-based noninvasive glucose sensor Shih developed as a Ph.D. student at the Massachusetts Institute of Technology. He holds two patents for technologies related to directly probing skin tissue using laser light to extract information about glucose concentrations.
The paper describes the development of a tiny device, built from multiple layers of gold nanowires stacked on top of a gold film and produced using solvent-assisted nanotransfer printing, which optimized the use of surface-enhanced Raman scattering to take advantage of the technique’s ability to detect small molecular samples.
Surface-enhanced Raman scattering – named for Indian physicist C.V. Raman, who discovered the effect in 1928 – uses information about how light interacts with a material to determine properties of the molecules that make up the material.
The device enhances the sensing properties of the technique by creating “hot spots,” or narrow gaps within the nanostructure which intensified the Raman signal, the researchers said.
Researchers created the glucose sensing contact lens to demonstrate the versatility of the technology. The contact lens concept isn’t unheard of – Google has submitted a patent for a multi-sensor contact lens, which the company says can also detect glucose levels in tears – but the researchers say this technology would also have a number of other applications.
“It should be noted that glucose is present not only in the blood but also in tears, and thus accurate monitoring of the glucose level in human tears by employing a contact-lens-type sensor can be an alternative approach for noninvasive glucose monitoring,” the researchers wrote.
“Everyone knows tears have a lot to mine,” Shih said. “The question is, whether you have a detector that is capable of mining it, and how significant is it for real diagnostics.”
In addition to Shih, authors on the paper include Yeon Sik Jung, Jae Won Jeong and Kwang-Min Baek, all with the Korea Advanced Institute of Science and Technology; Seung Yong Lee of the Korea Institute of Science and Technology, and Md Masud Parvez Arnob of UH.
Although non-invasive glucose sensing is just one potential application of the technology, Shih said it provided a good way to prove the technology. “It’s one of the grand challenges to be solved,” he said. “It’s a needle in a haystack challenge.”
Scientists know that glucose is present in tears, but Shih said how tear glucose levels correlate with blood glucose levels hasn’t been established. The more important finding, he said, is that the structure is an effective mechanism for using surface-enhanced Raman scattering spectroscopy.
Although traditional nanofabrication techniques rely on a hard substrate – usually glass or a silicon wafer – Shih said researchers wanted a flexible nanostructure, which would be more suited to wearable electronics. The layered nanoarray was produced on a hard substrate but lifted off and printed onto a soft contact, he said.
Suggested Items
Warm Windows and Streamlined Skin Patches – IDTechEx Explores Flexible and Printed Electronics
04/26/2024 | IDTechExFlexible and printed electronics can be integrated into cars and homes to create modern aesthetics that are beneficial and easy to use. From luminous car controls to food labels that communicate the quality of food, the uses of this technology are endless and can upgrade many areas of everyday life.
iNEMI Packaging Tech Topic Series: Role of EDA in Advanced Semiconductor Packaging
04/26/2024 | iNEMIAdvanced semiconductor packaging with heterogenous integration has made on-package integration of multiple chips a crucial part of finding alternatives to transistor scaling. Historically, EDA tools for front-end and back-end design have evolved separately; however, design complexity and the increased number of die-to-die or die-to-substrate interconnections has led to the need for EDA tools that can support integration of overall design planning, implementation, and system analysis in a single cockpit.
Koh Young Showcases Award-winning Inspection Solutions at SMTconnect with SmartRep in Hall 4A.225
04/25/2024 | Koh Young TechnologyKoh Young Technology, the industry leader in True 3D measurement-based inspection solutions, will showcase an array of award-winning inspection and measurement solutions at SMTconnect alongside its sales partner, SmartRep, in booth 4A.225 at NürnbergMesse from June 11-13, 2023. The following offers a glimpse into what Koh Young will present at the tradeshow:
Real Time with… IPC APEX EXPO 2024: Plasmatreat: Innovative Surface Preparation Solutions
04/25/2024 | Real Time with...IPC APEX EXPOIn this interview, Editor Nolan Johnson speaks with Hardev Grewal, CEO and president of Plasmatreat, a developer of atmospheric plasma solutions. Plasmatreat uses clean compressed air and electricity to create plasma, offering environmentally friendly methods for surface preparation. Their technology measures plasma density for process optimization and can remove organic micro-contamination. Nolan and Hardev also discuss REDOX-Tool, a new technology for removing metal oxides.
Nanotechnology Market to Surpass $53.51 Billion by 2031
04/25/2024 | PRNewswireSkyQuest projects that the nanotechnology market will attain a value of USD 53.51 billion by 2031, with a CAGR of 36.4% over the forecast period (2024-2031).