1. Departments of Molecular Biosciences, Chemistry, Chemical and Biological Engineering, and Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
2. Proteomics Center of Excellence, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
3. Beckman Institute and Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
4. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
5. Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, United States