1. The Maastricht MultiModal Molecular Imaging (M4I) institute, Division of Imaging Mass Spectrometry (IMS), Maastricht University, 6229 ER Maastricht, The Netherlands
2. AmberGen, Inc., 44 Manning Road, Billerica, Massachusetts 01821, United States
3. Molecular Biophysics Laboratory, Department of Physics and Photonics Center, Boston University, Boston, Massachusetts 02215, United States