1. College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, Jinan 250014, P. R. China
2. Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
3. Department of Chemical and Biological Engineering, University at Buffalo (SUNY), Buffalo, New York 14260, United States