EAPSI: Studying the surface chemistry of nanoplastics using super resolution microscopy

Oneil Colleen E, Chapel Hill NC

Investigators

Abstract

The ability to sequence the entire human genome has the potential to lead researchers and physicians to a better understanding of the implications of personal genetic differences in various diseases. This research aims to generate fundamental knowledge on the use plastic nanochannels with dimensions smaller than a human hair for the sequencing of DNA. The use of these devices for sequencing would lower the cost of sequencing, but very little is known about the surface chemistry of plastics on this scale. This research will be conducted in collaboration with Dr. Yoon-Kyoung Cho and Dr. Sang-Hee Shim at Ulsan National Institute of Science and Technology (UNIST). The unprecedented use of super-resolution microscopy instruments, available at UNIST, will allow for the first ever demonstration of surface characterization within plastic. To determine surface charge uniformity on the nanoscale, nanochannels will be modified with fluorescent tags. These modifications are facilitated through oxygen plasma activation to generate surface carboxylic acids and coupling to primary amines through EDC/NHS chemistry. Although modifications are possible, visualization of these modifications has yet to be achieved. Detection of the attachment of fluorescent molecules to indicate the uniformity of these modifications is not possible with conventional fluorescence microscopy due to the diffraction limit greater than nanoscale dimensions. Super resolution microscopy, such as Stochastic Optical Reconstruction Microscopy (STORM), can break these diffractions barriers and provide resolution as high as 20 nm. This research will utilize STORM to analyze the uniformity of surface modifications within various plastics various dimensions and various modification chemistries to compare with conventional fluorescence imagining. This research will be an unprecedented application of STORM for nanochannel research and will be essential for applications in nanochannel electrophoresis and next generation single molecule DNA sequencing. This NSF EAPSI award is funded in collaboration with the National Research Foundation of Korea.