Supporting Information

Transcription

1 Supporting Information Single Enzyme Direct Biomineralization of CdSe and CdSe-CdS Core-Shell Quantum Dots Zhou Yang 1, Li Lu 2, Christopher J. Kiely 1,2, Bryan W. Berger* 1,3, and Steven McIntosh* 1 1 Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA. 2 Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA 18015, USA. 3 Program in Bioengineering, Lehigh University, Bethlehem, PA 18015, USA. *mcintosh@lehigh.edu, berger@lehigh.edu S-1

2 Figure S1: Quantum yield as a function of incubation time for CdSe nanocrystals. Figure S2: HAADF-STEM images of individual CdSe nanocrystals after 24 h incubation with the corresponding FFT diagrams, demonstrating the formation of the wurtzite polymorph of CdSe. Table S1: Lattice fringes analysis based on HAADF-STEM images of CdSe nanocrystals after 24 h incubation shown in Figure S2 demonstrating the formation of wurtzite (WZ) CdSe. Figure S3: HAADF-STEM images of CdSe nanocrystals after 20 min incubation with the corresponding FFT diagrams, demonstrating the formation of both zinc blende and wurtzite -type CdSe. Table S2: Lattice fringes analysis based on HAADF-STEM images of CdSe nanocrystals after 20 min shown in Figure S3 demonstrating the formation of both zinc blende (ZB) and wurtzite (WZ) type CdSe. Figure S4: Absorbance of solutions incubated with the absence of one key component required for CdSe nanocrystal synthesis and TEM, EDXS analysis of Se nanoparticles. Figure S5: HAADF-STEM images of individual CdSe-CdS core-shell nanocrystals after 24 h incubation of the CdSe cores with the corresponding FFT diagrams, demonstrating the formation of the wurtzite polymorph of CdSe cores. Table S3: Lattice fringes analysis based on HAADF-STEM images of CdSe-CdS core-shell nanocrystals after 24 h incubation of the CdSe cores shown in Figure S5 demonstrating the formation of wurtzite (WZ) CdSe cores. Figure S6: BF-STEM images and single nanocrystal XEDS analysis for, 5.29 ± 1.56 nm CdSe- CdS core-shell nanocrystals. Figure S7: HAADF-STEM images of individual CdSe-CdS core-shell nanocrystals after 20 min incubation of the CdSe cores with the corresponding FFT diagrams, demonstrating the formation of both zinc blende and wurtzite type CdSe cores. Table S4: Lattice fringes analysis based on HAADF-STEM images of CdSe-CdS core-shell nanocrystals after 20 min incubation of the CdSe cores shown in Figure S7 demonstrating the formation of both zinc blende (ZB) and wurtzite type (WZ) CdSe cores. Figure S8: BF-STEM images and single nanocrystal XEDS analysis for, 3.21 ± 0.90 nm CdSe- CdS core-shell nanocrystals. S-2

3 Figure S1: Quantum yield of CdSe nanocrystals as a function of incubation time. S-3

4 Figure S2: HAADF-STEM images (a, c, e) of individual CdSe nanocrystals after 24 h incubation with the corresponding FFT diagrams (b, d, f), demonstrating the formation of the wurtzite polymorph of CdSe. S-4

5 Figure S2(a) Figure S2(c) Figure S2(e) WZ WZ WZ [001] [101 ] [33 1 ] Plane 1 d=3.80 Å 3.29 Å 1.98 Å d=3.16 Å d=2.05 Å (100) (101) (103) Plane 2 d=3.76 Å 3.29 Å 2.15 Å d=3.33 Å d=2.18 Å (11 0) (11 1) (110) Plane 3 d=3.57 Å 1.98 Å d=3.75 Å d=2.12 Å (010) (010) (013 ) <1, 2> <2, 3> <3, 1> Table S1: Lattice fringe analysis based on HAADF-STEM images of CdSe nanocrystals after 24 h incubation shown in Figure S2 demonstrating the formation of wurtzite (WZ) CdSe. The three CdSe nanocrystals are viewed along the [001], [101 ] and [33 1 ] zone axes, respectively. S-5

6 Figure S3: HAADF-STEM images of CdSe nanocrystals after a) and c) 20 min incubation with (b, d) the corresponding FFT diagrams, demonstrating the formation of both zinc blende (a) and wurtzite (c) type CdSe. S-6

7 Figure S3(a) Figure S3(c) ZB [11 0] WZ [001] Plane 1 d=3.66 Å 3.49 Å (111) d=3.53 Å (100) Plane 2 d=3.56 Å 3.49 Å (111 ) d=3.62 Å (11 0) Plane 3 d=3.20 Å 3.02 Å (002) d=3.70 Å (010) <1, 2> <2, 3> <3, 1> Table S2: Lattice fringes analysis based on HAADF-STEM images of CdSe nanocrystals after 20 min incubation shown in Figure S3 demonstrating the formation of both zinc blende (ZB) and wurtzite (WZ) type CdSe. The two CdSe nanocrystals are viewed along the ZB [11 0] and WZ [001] zone axes, respectively. S-7

8 Figure S4: a) Absorbance spectra of samples lacking in one of the key components measured after 24 h incubation. The sample lacking Cd acetate (red line) shows absorption and coloration consistent with the formation of Se particles. b) TEM image and c) XEDS spectra confirms the formation of Se. P and Cl are residual from enzyme preparation. S-8

9 Figure S5: HAADF-STEM images (a, c, e) of individual CdSe-CdS core-shell nanocrystals after 24 h incubation of the CdSe cores with the corresponding FFT diagrams (b, d, f), demonstrating the formation of the wurtzite polymorph of CdSe cores. S-9

10 Figure S5(a) Figure S5(c) Figure S5(e) WZ WZ WZ WZ [101 ] [24 1] [14 2 ] [001] Plane 1 d=3.26 Å 3.29 Å 1.59 Å 1.58 Å d=1.47 Å d=3.60 Å (101) (014) (21 3) (100) Plane 2 d=3.41 Å 3.29 Å 1.83 Å 1.80 Å d=1.72 Å d=3.84 Å (11 1) (112) (201) (11 0) Plane 3 d=3.73 Å 2.55 Å 2.55 Å d=2.70 Å d=3.88 Å (010) (102 ) (012 ) (010) <1, 2> <2, 3> <3, 1> Table S3: Lattice fringes analysis based on HAADF-STEM images of CdSe-CdS core-shell nanocrystals after 24 h incubation of the CdSe cores shown in Figure S5 demonstrating the formation of wurtzite (WZ) CdSe cores. The three CdSe-CdS core-shell nanocrystals are viewed along the [101 ], [24 1 ] or [14 2 ], and [001] zone axes, respectively. S-10

11 Figure S6: Electron microscopy characterization of some large size core/shell CdSe/CdS QDs. (ac) images of single core CdSe QDs (highlighted in red box). (d) Typical single particle energydispersive X-ray spectroscopy (XEDS) analysis. Ni and Si signals are from the Ni-based TEM grid and the XEDS detector, respectively. (e) Calculated atom ratio of Cd:Se:S from the XEDS spectra obtained from the particles shown in figs. a-c. The average estimated layer thickness of the CdS shell is about 0.3 monolayer. S-11

12 Figure S7: HAADF-STEM images (a, c, e) of individual CdSe-CdS core-shell nanocrystals after 20 min incubation of the CdSe cores with the corresponding FFT diagrams (b, d, f), demonstrating the formation of both zinc blende (a) and wurtzite (c, e) CdSe cores. S-12

13 Figure S7(a) Figure S7(c) Figure S7(e) ZB WZ WZ WZ [11 0] [010] [011] [001] Plane 1 d=3.57 Å 3.49 Å 3.51 Å d=3.56 Å d=3.84 Å (111) (002) (100) (100) Plane 2 d=3.18 Å 3.02 Å 3.29 Å 3.29 Å d=3.25 Å d=3.47 Å (002) (101) (011 ) (11 0) Plane 3 d=3.50 Å 3.49 Å 3.29 Å 3.29 Å d=3.38 Å d=3.55 Å (111 ) (101 ) (11 1) (010) <1, 2> <2, 3> <3, 1> Table S4: Lattice fringes analysis based on HAADF-STEM images of CdSe-CdS core-shell nanocrystals after 20 min incubation of the CdSe cores shown in Figure S7 demonstrating the formation of both zinc blende (ZB) and wurtzite (WZ) type CdSe cores. The three CdSe-CdS coreshell nanocrystals are viewed along the ZB [11 0], WZ [010] or WZ [011], and WZ [001] zone axes, respectively. S-13

14 Figure S8: Electron microscopy characterization of some small size CdSe-CdS core-shell QDs. (a-c) BF-STEM images of single core CdSe QDs (highlighted in red box). (d) Typical single particle energy-dispersive X-ray spectroscopy (XEDS) analysis. Ni and Si signals are from the Nibased TEM grid and XEDS detector, respectively. (e) Calculated atom ratio of Cd:Se:S from the XEDS spectra obtained from the particles shown in figs a-c. The average estimated layer of CdS shell is about 1.1 monolayer. S-14