Supporting Information

Transcription

1 Supporting Information From the Aggregation-Induced Emission of Au(I)-Thiolate Complexes to Ultra- Bright Core-Shell Nanoclusters Zhentao Luo, a Xun Yuan, a Yue Yu, a Qingbo Zhang, b David Tai Leong, a Jim Yang Lee a and Jianping Xie a* a Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore b Department of Chemistry, Rice University, Houston, US 1892 AUTHOR ADDRESS: chexiej@nus.edu.sg S1

2 Figure S1. PAGE results for (a) Au m SG n NCs reported by Negishi et al. 1 (under visible light), (b) the as-synthesized Au(0)@Au(I)-thiolate NCs (under UV light), and (c) the oligomeric Au(I)-thiolate complexes (under UV light). The table shows the molecular formula of Au NCs in outlined bands in (a) and (c). Figure S2. Digital photos of (a) the oligomeric Au(I)-thiolate complexes, and the aggregated complexes induced by (b) ethanol (95% of ethanol by volume) and (c) Cd 2+ ions (with Cd 2+ -to-gsh ratio of 1:2). Cuvettes in (a) to (c) were irradiated by a red laser beam. The test setup for the Rayleigh scattering is shown in (d). S2

3 Figure S3. Photoluminescence decay profiles of Au(I)-SG complexes aggregated by (a) ethanol (95% of ethanol by volume) and (b) Cd 2+ ions (with Cd 2+ -to-gsh ratio of 1:2), and (c) the as-synthesized luminescent Au NCs in water. The upper portion of each image is an exponential fit of the experimental data, and the lower portion of each image shows the residuals of fitting. Table S1. Summary of lifetimes of the aggregated Au(I)-SG complexes and the as-synthesized luminescent Au NCs (λ em = 610 nm and λ ex = 344 nm) Sample τ 1 (ns) (Rel. Ampl) τ 2 (ns) (Rel. Ampl) τ 3 (ns) (Rel. Ampl) τ 4 (ns) (Rel. Ampl) Aggregated Au(I)-SG complexes Ethanol-induced (95 vol%) Cd 2+ -induced (Cd 2+ -to-gsh ratio of 1:2) 2930 (85%) 2410 (79%) 455 (14%) 355 (18%) 54 (1.5%) 39 (3.0%) 0.43 (8.6%)* 0.09 ( )* Luminescent Au NCs In water 1990 (61%) 536 (29%) 144 (8.9%) 19 (1.5%) * Lifetimes of the scattered light from the aggregated complexes. S3

4 Figure S4. The average sizes of the aggregates of oligomeric Au(I)-SG complexes at different f e (Vol ethanol /Vol ethanol+water ) measured using dynamic light scattering (DLS). Figure S5. Digital photos of the oligomeric Au(I)-thiolate complexes in the solid state (vacuum-dried) under visible (item 1) and UV (item 2) light. S4

5 Figure S6. ESI mass spectra of (a) the reaction solution of as-synthesized luminescent Au NCs, and (b) the aqueous solution of pure GSH (3 mm) after heating at 70 C for 24 h. The most abundant species in (a) are GS-SG (at m/z 305 and 611 which are assigned to [GS-SG 2H] 2- and [GS-SG H] - respectively) and the sulfonic acid derivative of GSH (at m/z 354 which is assigned to [M H] - ; see the molecular structure of M in the inset). The base peak in (b) corresponds to GSH (at m/z 306 which is assigned to [GSH H] - ). The above ESI-MS analyses confirmed the reducing role of both thiol (in GSH) and disulfides (in GS-SG) in our reaction system. S5

6 Figure S7. Time-course UV-vis absorption (dashed lines) and photoemission (solid lines) spectra of the as-synthesized luminescent Au NCs in various experimental conditions: (a) in water at 25 C, (b) in water at 80 C, (c) in 1 M NaCl solution at 25 C and (d) in a 40 mm HEPES buffer solution (ph 7) at 25 C. S6

7 Figure S8. The analysis of the isotope distribution of the most intense peak of the deconvoluted ESI mass spectrum of Band 2. (a) and (b) are the mass spectra of Band 2. (c) to (e) are the comparison between the shifted mass spectrum of Band 2 (red lines, the shifted mass is 135, 47 and 156 Da for (c) to (e), respectively) and the simulated isotope distributions (black lines) of three Au NCs formulas with the increase of the number of SG ligands from 27 to 29. Since the abundance of 197 Au is %, the isotope distribution of the Au NCs is determined by the number of SG ligands. The isotope distribution of 28 SG ligands shows the closest match to the experimental isotope distribution, therefore the most intense peak of Band 2 can be assigned to Au 30 SG 28. The m (= 129 Da) in (a) indicates a loss of glutamic acid residue due to the partial hydrolysis of GSH. 2 S7

8 Figure S9. Digital photos of the product synthesized by reacting HAuCl 4 (2 mm) and GSH (3 mm) at 25 C for 24 h. The product was viewed under visible (item 1) and UV (item 2) light. Insoluble aggregates of Au(I)-thiolate complexes can be observed at the bottom of the vial. Figure S10. UV-vis absorption spectrum of Au nanocrystals prepared by mixing HAuCl 4 (20 mm, 0.5 ml) and GSH (100 mm, 0.15 ml) with ultrapure water (3.6 ml) at room temperature for 10 min, followed by the addition of NaBH 4 (200 mm, 0.75 ml, 0 C); and the mixture was allowed to react for 3 h at 25 C. The inset shows the digital photos of the product under visible (item 1) and UV (item 2) light. S8

9 Figure S11. Digital photos of the products synthesized by mixing HAuCl 4 (2 mm) and GSH with different GSH-to-Au ratios: (a) 0.5:1, (b) 1.5:1, and (c) 2:1, at 70 C for 24 h. The vials were viewed under visible (upper row) and UV (lower row) light. Figure S12. Digital photos of the as-synthesized Au(0)@Au(I)-thiolate NCs in a 250-mL round-bottom flask under visible (item 1) and UV (item 2) light. References (1) Negishi, Y.; Nobusada, K.; Tsukuda, T. J. Am. Chem. Soc. 2005, 127, (2) Shichibu, Y.; Negishi, Y.; Tsukuda, T.; Teranishi, T. J. Am. Chem. Soc. 2005, 127, S9