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