[Thu. 12 Oct. 2017] Student Host Colloquium : Versatile Dendrimer-Encapsulated Nanoparticles for Analytical Applications

“Versatile Dendrimer-Encapsulated Nanoparticles for Analytical Applications”

There are two main topics presented here. The first topic is the synthesis of dendrimer-encapsulated nanoparticles (DENs) and their useful properties for analytical applications. Specifically, we synthesized Pt DENs containing an average of 55 Pt atoms using amine-terminated 4th-generation polyamidoamine (PAMAM) dendrimers, which we denote as G4-NH2(Pt55). The synthesized G4-NH2(Pt55) exhibited peroxidase-mimetic activity, superior or at least comparable to that of natural peroxidase enzymes such as horse radish peroxidase (HRP), and thus could be utilized as peroxidase-mimetic labels for sensitive colorimetric assays. In addition, we synthesized Pt DENs using amine-terminated nth generation PAMAM (Gn-NH2, n = 6 and 4) dendrimers. The synthesized Pt DENs showed different sizes over the range of 1-3 nm, but were fairly uniform and monodispersed in size with subnanometer accuracy. Interestingly, we found the size-dependent catalytic activity of the Pt DENs having well-defined sizes with subnanometer accuracy for the enhanced chemiluminescence of the luminol/H2O2 system. We demonstrated the analytical versatility of the Pt DEN-catalyzed generation of chemiluminescence in oxidase-based analyses toward various oxidase substrates including choline, glucose, and cholesterol. The second topic is the functionalization of chip surfaces with DENs for fabrication of versatile chip-based analytical platforms. Two types of surface decoration methods will be mainly discussed: electrochemical decoration of glassy carbon and indium tin oxide surfaces, and covalent decoration of chemically converted graphene (CCG) surfaces. A brief description will be also presented how the chip-based analytical platforms can be applied as electrochemical, optical, and electrochemiluminescence (ECL) sensor chips based on the various transduction techniques.

Reference

1. Kwon, J.; Park, S. K.; Lee, Y.; Lee, J. S.*; Kim, J.* Biosens. Bioelectron., 2017, 87, 89-95.

2. Lim, H.; Ju, Y.; Kim, J.* Anal. Chem., 2016, 88, 4751-4758.

3. Ju Y.; Kim, J.* Chem. Commun., 2015, 51, 13752-13755.

4. Kim, Y.; Kim, J.* Anal. Chem., 2014, 86, 1654-1660.

5. Kim, J. M.; Kim, J.*, Song, J. K.* et al. ChemPhysChem, 2014, 15, 2917-2921.

6. Yoon, J.; Kim, H.-S.*, Kim, J.* et al. Chem. Commun., 2014, 50, 7670-7672.

7. Lee, S. B.; Ju, Y.; Kim, Y.; Koo, C. M.; Kim, J.* Chem. Commun., 2013, 49, 8913-8915.

8. Kim, J. M.; Kim, J.; Kim, J.* Chem. Commun., 2012, 48, 9233-9235.

9. Ju, H.; Koo, C. M.; Kim, J.* Chem. Commun., 2011, 47, 12322-12324.

10. Kim, T. H.; Choi, H. S.; Go, B. R.; Kim, J.* Electrochem. Commun., 2010, 12, 788-791.

Prof. Joohoon Kim

Department of Chemistry, Kyung Hee University, Korea