<p> SUPPORTING INFORMATION</p><p>A new rhodamine based ‘turn-on’ Cu2+ ion selective chemosensor in aqueous system applicable in bioimaging</p><p>ABHISHEK MAJI, SOMENATH LOHAR, SIDDHARTHA PAL and PABITRA CHATTOPADHYAY* Department of Chemistry, The University of Burdwan, Golapbag, Burdwan, West Bengal 713 </p><p>104, India</p><p>CONTENTS</p><p>S1 HRMS spectrum of L...... Figure S1 1H NMR spectrum of L...... ….………………………………...... Figure S2 FT-IR spectrum of L………………………………………...... Figure S3 Interference of different cations in presence of L and Cu2+ ions……… Figure S4 Mass spectra of L due to the addition of Cu2+ ions Figure S5 FT-IR spectrum of L in presence of Cu2+ ions ………………...... Figure S6 Emission profile of L in presence of Cu2+ ions with increase in time...... Figure S7 Linear response curve of L as a function of Cu2+ ions concentration…. Figure S8 Cytotoxic effect of L.….………………………………………………. Figure S9</p><p>S2 Figure S1. HRMS spectrum of L</p><p>S3 Figure S2. 1H NMR spectrum of L</p><p>S4 Figure S3. FT-IR spectrum of L</p><p>Figure S4. Interference of different ions (50 µM) in presence of L (20.0 µM) and Cu2+ ions (20.0 µM) in 10% ACN 20 mM HEPES buffer (pH 7.4) at 25 oC (A) Ni2+, (B) Cr3+, (C) Al3+, (D) Mg2+, (E) Zn2+, (F) Pb2+, (G) Fe2+, (H) Fe3+, (I) Cd2+, (J) Co2+, (K) Mn2+, (L) Ca2+, (M) Ba2+, (N) Na+, (O) K+ and (P) Hg2+.</p><p>S5 Figure S5. Mass spectra of L due to the addition of Cu2+ ions</p><p>Figure S6. FT-IR spectra of L in presence of Cu2+ ions</p><p>2+ Figure S7. Emission (at em = 572 nm) profile of L in presence of Cu ions (1 equivalent) with increase in time (min.)</p><p>S6 Figure S8. The linear response curve of the emission of L at 572 nm depending on Cu2+ ions concentration</p><p>Figure S9. Cytotoxic effect of L (5, 10, 25, 50 and 100 μM) in AGS cell incubated for 8 h</p><p>S7</p>