Joseph Caissie Bush
Joe is a chemist with interest to practical applications. Specifically with regard to the design of analytical devices to improve our understanding of chemical dynamics and structure.
In the stimulating environment of Prof. Peter Weber’s lab, Joe learned about ultra-fast, pump-probe, photoelectron/photofragmentation spectroscopy, ion optic design, and mass spectrometry. The specific technique developed by Prof. Weber utilizes Rydberg states as an electronic intermediate, where the electron spatial wave function encompasses the entire molecular structure and hence it’s energy is sensitive to the global structure of the molecule. Joe’s thesis work investigated the structural dynamics of N,N-dimethylphenethylamine (PENNA) as initiated by a photo induced cation-pi interaction.
This molecular system was chosen as a model for larger biological systems because of it’s closely coupled functional groups, and flexible backbone. It’s dynamics are contrasted with the hydrogenated analog (N,N-dimethyl,cylcohexylethylamine, CENNA), which lacks the delocalized electron density of the phenyl-ring, which provides the driving attractive potential to the nascent positive charge on the amine.
Throughout graduate school Joe was an active participant in the Chemistry department and the University at large. Being an active participant in seminars and taking a role in student governance, he gained a broad perspective on the science of chemistry and the larger picture of institution dynamics. He was elected to the role of president of the graduate student council and with that role sat on the Brown University community council (BUCC), a forum comprised of members of the staff, faculty, and administration and run by the University President to discuss issues at large with the institution. He remained active on the BUCC for several years after he tenure on the graduate student council ended.
Since completing his Ph.D. he has been working as a post doctoral research associate in the department of physics at Brown in the lab of Derek Stein. The project focus is on the application of chip based nanopores as an ion source for single molecule DNA sequencing by mass spectrometry. The goal is to use a nanopore to define a liquid-vacuum interface. By applying large electric fields across the pore, ions will be field emitted. The result will be a uniquely spatially defined single ion source. The application to DNA sequencing will rely on the nanopore to restrict the spatial orientation of DNA such that is processes linearly through the pore, where it will be sequentially be fragmented and directed into the entrance of a mass spectrometer, where the sequence will be read as a temporal sequence of ion masses. More to come…..
Music, such as playing the guitar, mandolin, or harmonica,
biking, basketball, squash, and just plain walking,
fish tanks, wildlife, star-gazing,
literature, film, and theater.