Univ of Illinois Micro + Nanotechnology Lab 2016 Highlights Report | Page 9

The FlexBrite photonic sensor
Smallest and most stable quantum dots
A thin , bendable plastic-based wafer , FlexBrite contains nano-scale bumps that bend light and change color allowing researchers to analyze liquids quickly and efficiently . FlexBrite was developed by ECE faculty member Logan Liu ’ s research group .

The FlexBrite photonic sensor

ECE Associate Professor Gang Logan Liu and his group have developed an innovative label-free molecule detection method that can quickly determine the content and quantity of substances in a liquid . Their FlexBrite photonic sensor could someday be used to check for pollutants in water , monitor food safety , or determine the amount of ethanol in gasoline . FlexBrite successfully combines naked-eye plasmonic colorimetry and surface-enhanced Raman spectroscopy ( SERS ) in one sensor — the first time this has been accomplished . At first glance , FlexBrite is a thin , bendable , plastic-based wafer that shines purple in the light . At the nanoscale , however , it ’ s crisscrossed with tiny bumps or nano-mushrooms that bend the light reflected off them and account for FlexBrite ’ s color-changing properties , allowing researchers to analyze liquids much more efficiently . Liu is exploring commercializing this technology since it currently costs about $ 2 / cm 2 to fabricate compared to $ 40- $ 120 per chip for existing SERS sensors .
Source : Nanoscale , “ Large-area , uniform and low-cost dual-mode plasmonic naked-eye colorimetry and SERS sensor with handheld Raman spectrometer ,” issue 11 , February 15 , 2016

Smallest and most stable quantum dots

Quantum dots , or fluorescent nanocrystals , are a promising alternative to organic and fluorescent dyes for detecting and imaging proteins and nucleic acids , but their large size ( 15-35 nanometers ) has limited their use . In 2016 , Bioengineering Assistant Professor Andrew Smith and his students were able to optimize a coating strategy for making quantum dots , which allowed them to produce some of the smallest ( 7.4 nanometers ) and most stable quantum dots to date . The team also demonstrated the usefulness of click chemistry in the process , which could enable quantum dots to be used in crowded macro-molecular environments like the neural synapse and cellular cytoplasm . Ultimately , Smith and Physics Professor Paul Selvin aim to use quantum dots to study how molecules behave in a healthy brain compared to a brain afflicted with Alzheimer ’ s disease .
Sources : Journal of the American Chemical Society , “ Multidentate polymer coatings for compact and homogeneous quantum dots with efficient bioconjugation ,” 138 ( 10 ), February 10 , 2016 .
Bioengineering faculty member Andrew Smith ’ s group has developed a new coating method that enables the creation of smaller quantum dots that could be used for studying crowded macro-molecular environments like the neural synapse and cellular cytoplasm .
micro + nanotechnology lab | 7 | 2016 highlights report