1. School of Engineering, University of Warwick, CV4 7AL, Coventry, UK
2. Department of Chemistry, University of Warwick, CV4 7AL, Coventry, UK
3. Spectroswiss, EPFL Innovation Park, 1015, Lausanne, Switzerland
4. Department of Chemistry and Biochemistry, Department of Biological Chemistry, David Geffen School of Medicine, and UCLA/DOE Institute of Genomics and Proteomics, University of California, Los Angeles, CA, USA