(2s) Precise Manufacturing of Advanced Materials Driven By Atomic Scale Characterization

Research Interests

Hormones and enzymes trigger and regulate several functions of the human body. These biomolecules are composed of proteins consisting of amino acids that serve as primary building blocks. Changes in the local conformations of a single amino acid in enzymes can result in mutations that are specific to a certain disease. These mutations are typically detected through spectrophotometry, fluorescence, and radiolabeling techniques with limited resolution and long acquisition times. Chiroptical imaging and spectroscopy provides an exciting avenue for rapid diagnosis by detecting changes in electronic transitions and molecular vibrations. However, the technique is limited in applicability due to (i) the weakly scattering nature of organic amino acids and (ii) spectral overlap with non-mutated amino acids. These limitations can be overcome by fabricating precise interfaces with controlled porosity and chirality that allows the biomolecules to diffuse through the pores and couple with hybrid interfaces extending over 100s of nanometers with the desired surface chemistry. Charge transfer between transition metal ions and biomolecules gives rise to coupled atomic vibrations that amplify the scattered intensity (sensitivity) and have a unique fingerprint spectroscopically (specificity).

My research program will develop chiral interfaces by exploring both fundamental and applied research questions listed below –

1. How is structural chirality transferred from molecules to a collection of nanoparticles?
2. What is the correlation between multi-scale structural and hyperspectral optical chirality? and,
3. Can precious noble metals be replaced by transition metals for biosensing?

I will describe my strategies for addressing these questions by combining my expertise in colloidal chemistry, [1-2] aberration corrected transmission electron microscopy, [3-4] and chiroptical spectroscopy [1,5,6].

Selected Publications

Total – 29 publications, cited 2016 times (^¶ Corresponding author, * Co-first Author)

[1] Kumar, P., Vo, T., Cha, M. et al. Photonically active bowtie nanoassemblies with chirality continuum. Nature 615, 418–424 (2023) (Cover article).

[2] Gao, R.*, Xu, X.*, Kumar, P.* et al. Targeted Agglutination of Corona Virus by Tapered Chiral Nanoparticles. (Manuscript under review) DOI: 10.21203/rs.3.rs-2501398/v1

[3] Kumar, P. ^¶ et al. One-dimensional intergrowths in two-dimensional zeolite nanosheets and their effect on ultra-selective transport. Nature Materials, 19, 443–449 (2020).
[4] Kumar, P. et al. Quantification of thickness and wrinkling of exfoliated two-dimensional zeolite nanosheets. Nature Comms., 6, 7128 (2015).

[5] Kumar, P.^¶ et al. Enantiomeric Discrimination by Chiral Electromagnetic Resonance Enhancement. Chirality, Accepted (2023).

[5] Kumar, P. et al. Tunable Sub-Wavelength Structuring of Anisotropic Optical Scatterers into Hedgehogs with Form Birefringence. (Manuscript in preparation).

Background

I am a Materials Scientist developing materials at the interface of chemical and biomolecular engineering for separation of isomers, single-atom catalysis, and chiroptical sensing of biomolecules. I completed my undergraduate degree from the Department of Metallurgical Engineering and Materials Science at Indian Institute of Technology, Madras (IITM) in 2012. I received my PhD degree in the Departments of Chemical Engineering and Materials Science at the University of Minnesota, along with a minor degree in the Department of Chemistry. My doctoral research, advised by Prof. K. Andre Mkhoyan and Prof. Michael Tsapatsis, was focused on developing the area of two-dimensional (2D) porous materials using analytical transmission electron microscopy (TEM). This body of work benefits the field of energy-efficient molecular separation, in terms of achieving the highest separation selectivity for xylene isomers by designing the optimized material. I graduated with my Ph.D. in August 2018 and started working with Prof. Nicholas A. Kotov at the Biointerfaces Institute at the University of Michigan, Ann Arbor. My current research focuses on the multi-scale synthesis of porosity and chirality using biomimetic self-assembly of amino acids and metal ions. I have been awarded the Doctoral Dissertation Fellowship by the University of Minnesota and graduate student awards by the Microscopy Society of America (MSA) and Materials Research Society (MRS). I have also received the Biointerfaces Institute postdoctoral innovator award. I am passionate about microscopy and use it to inspire the next generation of scientists to pursue a career in STEM fields.

Teaching interests

I believe framing a question requires an in-depth knowledge of concepts. As a materials chemist, my goal is to impart a fundamental understanding of material properties so that my students can pose the following questions from even a mundane observation like the tearing of a plastic grocery bag - Why does the bag stretch before snapping? How much weight can the bag withstand? Could I design another polymer that is equally convenient but environmentally friendly? Subsequently, they should be able to break the problem into parts and seek out interdisciplinary teams to engineer solutions to their questions.

I have a strong desire to teach and mentor students from diverse backgrounds. At the University of Minnesota, I have taught a material testing laboratory course at the undergraduate level and served as a teaching assistant for both undergraduate and graduate courses. At the University of Michigan, I have completed a semester-long certificate program on teaching and mentoring methodologies with the Center for Research on Learning and Teaching. I have mentored three undergraduate and several graduate students which has resulted in co-authored, and first-author peer-reviewed publications highlighted above. As a teacher, I want to share my atomic-scale perspective of materials chemistry with students through introductory and advanced courses such as Thermodynamics, Transport Phenomena, Introduction to Materials Science, Electronic Properties of Materials, and Particle Science and Technology. I will also develop courses in Analytical Transmission Electron Microscopy and Digital Signal Processing for Engineers.