Larry Tesler




Office: CLB302



University of Florida
Ph.D. in Analytical Chemistry, 2014-present
Graduate Research Project with Dr. Nick Polfer
Mass Spectrometry


University of Florida
B.S Chemistry and Physics summa cum laude, August 2014.
B. A. Mathematics magna cum laude, August 2014.
Undergraduate Research Interest:


Research Interests:

My primary research focus in the Polfer group is cryogenic vibrational ion spectroscopy. In vibrational ion spectroscopy, the structure of an ion is probed by monitoring the dissociation of an ion after exposure to a light source with a specific frequency that corresponds to an ion’s vibrational modes. In our lab, we utilize a tunable optical parametric oscillator (OPO) light source to scan through a number of frequencies and quantify the degree of light absorption, by the ions, at each frequency. This technique is also referred to infrared photo dissociation spectroscopy (IRPD); however, the dissociation of an ion requires the breaking of covalent bond, which entails the absorption of multiple photons; this is called infrared multiple photon dissociation (IRMPD), and has several limitations because of these non-linear effects of multiple photon absorption. By going to cryogenic temperatures, we can tag the ions with an inert gas because of Van der Waals interactions. The dissociation of the tag only requires a single infrared photon, so the limitations of IRMPD can be overcome.



For my part in the Polfer group, I have assisted in the development and operation of a mass-selective cryogenic linear ion trap (CryoLIT), primarily in the setup of the electronic systems required to operate it. Since the linear ion trap is mass-selective. Ions can be tagged and isolated in the same trap, allowing IRPD to be performed in a single mass analyzer, which can yield some benefits such as improved sensitivity and the potential to obtain the infrared spectra of several ions simultaneously.


In order to better understand how these linear ion traps operate and characterize their performance without having to run actual experiments, I have used SIMION (an ion trajectory simulator) to simulate how ions behave in our cryogenic linear ion trap. SIMION allows a user to write scripts in the Lua programming language, which can add additional functionality to the simulation. With Lua, additional effects such as tickle waveforms, ion-neutral collisions, and space charge, can be simulated, or values can be recorded when certain conditions are met (e.g. ions exiting the linear ion trap).



Outside of cryogenic infrared spectroscopy, my interests involve automation, electronic design, and programming. My programming language of choice in the Polfer group is Python, which I have used for calculation of Stored Waveform Inverse Fourier Transform (SWIFT) waveforms and for general data processing. Additionally, I have used python for the development of a webserver that is used to automate the various instruments found in our lab for greater research efficiency.



I have also developed several ARM microcontroller devices to control the timing and voltages of our custom mass spectrometer. These microcontrollers offer many peripherals that can be accessed with only a couple of clock cycles. This means that real time control and accurate timing can be achieved. Additionally, compared to more dedicated/specific solutions, they are fairly cheap ($10-30). These microcontroller devices are programmed in C++, which allows efficient manipulation of peripheral registers.





'Making Mass Spectrometry See the Light: The Promises and Challenges of Cryogenic Infrared Ion Spectroscopy as a Bioanalytical Technique', AP Cismesia, LS Bailey, MR Bell, LF Tesler, NC Polfer; J. Am. Soc. Mass Spectrom., 2016


'Effects of ESI conditions on kinetic trapping of the solution-phase protonation isomer of p-aminobenzoic acid in the gas phase', AL Patrick, AP Cismesia, LF Tesler, NC Polfer; Int. J. Mass. Spectrom., 2017.


'Infrared ion spectroscopy inside a mass-selective cryogenic 2D linear ion trap', AP Cismesia, LF Tesler, MR Bell, LS Bailey, NC Polfer; J. Mass Spectrom., 2017.