Electronic Supplementary Information (ESI) A Highly Selective Ratiometric Near-infrared Fluorescent Cyanine Sensor for Cysteine with Remarkable Shift and Its Application Bioimaging Zhiqian Guo 1,2 , SeongWon Nam 1 , Sungsu Park 1 * and Juyoung Yoon 1 * 1 Departments of Chemistry and Nano Science and Departments of Bioinspired Science (WCU), Ewha Womans University, Seoul 120-750, Korea 2 Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, Shanghai 200237, P. R. China. E-mail: nanopark@ewha.ac.kr; jyoon@ewha.ac.kr; Table of Contents Table S1. Chemical shifts of alkene-H in IR-780, CyAK and CyAC Figure S1. Time dependence of CyAC (5.0 μM) with the addition of 50 μM Cys in absorption and emission spectra Figure S1. Absorbance responses of CyAC with all kinds of amino acids Figure S3. (A) Excitation spectra of CyAC (5.0 μM) with the titration of Cys (λ ex =780 nm); (B)Absorption spectra and (C) Emission spectra change of CyAC as a function of concentration Cys (0-25μM) Figure S4. Spectra proprieties of CyAC (5.0 μM) with 50 μM Hcy Figure S5. Spectra proprieties of CyAC (5.0 μM) with 50 μM GSH Figure S6. Kinetic Studies of CyAC with Cys, Hcy, and GSH. Electronic Supplementary Material (ESI) for Chemical Science This journal is © The Royal Society of Chemistry 2012