Metal Nanoparticles@ Metal-Organic Frameworks (MOFs) Metal Nanoparticles@ Metal-Organic Frameworks (MOFs). Synthesis and evidences of Molecule Diffusion beyond the Aperture Size Limit Guangchao Zheng1*, Vanesa López-Puente1, Sergio Rodal- Cedeira1, Lakshminarayana Polavarapu1, Luis M. Liz- Marzán1,2, Isabel Pastoriza-Santos1, Jorge Pérez-Juste1*   1 Departamento de Química Física, Universidade de Vigo, 36310 Vigo, Spain 2 BNP Laboratory, CIC biomaGUNE, Paseo de Miramón 182, 20009 Donostia, Spain Email: gczheng@uvigo.es

Outline Introduction & Objectives Synthesis Plasmonic nanoparticles (NPs) @ Zeolitic imidazolate frameworks (ZIF-8) Molecule Diffusion through the ZIF-8 shell Conclusions

1.1 MOFs ZIF-8 1) Synthesis at the grame scale 2) Crystalline, High surface area, Porosity can be adjusted and chemical stablility. Phys. Chem. Chem. Phys., 2014,16, 9940-9949 ZIF-8 Size-selective catalysis and sensing; gas sensing and storage

CTAB functionalize Zif-8 (D) (E) CTAB 0.025% CTAB No CTAB 0.25% CTAB CrystEngComm, 2011, 13, 6937–6940

1.2 Integration of NPs with MOFs 1.2.1 Synthesis approaches: Approach 2 (B) Approach 1 (A) J. Am. Chem. Soc. 2011, 133, 1304–1306 Nat Chem 2012, 4 (4), 310-316.

Size-selective catalysis 1.2.2 Applications (A) (B) Size-selective catalysis Adv. Mater. 2014, 26, 4056–4060

Size-selective sensing (A) Size-selective sensing Quantum dots MOFs How does the molecule selective diffuse through the MOFs ? How does it rely on the pore size and aperture size? (B) What! Nature communications, DOI: 10.1038/ncomms1234

2.1 AIM: Integration NPs with MOFs & SERS Great! Step 2 Step 1

2.2 SERs Au NRs Au nanostars Au@Ag NRs

2.3 Preparation of the Plasmonic NPs@Zif-8 200nm A B D

2.3 Mapping of Au@Ag@Zif-8 A B C D E F G H

2.4 Monitor the growth of MOFs on the surface of Au@Ag core-shell NPs B D C A

2.5 CTAB sufactant tune the size growth of Zif-8 Thickness (nm) Count A B C D (A) 0.84mM, (B) 0.061 mM and (C) 0.084mM of CTAB.

2.6 Molecules Size-selective diffusion Table Structure Characteristics of Zif-8 calculated from single crystal x-ray analysis PNAS , 2006, 103, 10186–10191 . MGI NAT NBT

2.6 Molecules Size-selective diffusion A B (A) SERs spectra of the molecular probes used to test the diffusion through the Zif-8 shell. The shadow regions indicate the bands followed during the diffusion studies. (B) Kinetic trace of the diffusion of each probe through the Zif-8 shell based on their SERs intensity.

3 Conclusions We have developed a general strategy for the Zif-8 encapsulation of individual metal nanoparticles. The SERs properties of the metal nanoparticles cores allowed us to study the transport of different guest molecules through the Zif-8 shell. The analysis of the results showed that it was mainly a diffusion process with size dependent rates (the larger the molecule the slower the rate of diffusion).

Thanks for their lots of help. Acknowledgement Isabel Pastoriza-Santos Jorge Pérez-Juste Luis M. Liz-Marzán Vanesa López-Puente Sergio Rodal-Cedeira Thanks for their lots of help.

Thanks for your attention.

Au (simulated) Zif-8 (simulated) Au@Zif-8