Tuning the Generation of Luminescent Silver Nanodots with Printed ssDNA on the Surface

When and Where

Apr 10, 2023
3:30pm - 3:45pm

Moscone West, Level 3, Room 3016

Presenter

Junhua Yu

Sungmoon Choi

Co-Author(s)

Junhua Yu¹,Sungmoon Choi¹

Seoul National Univ¹

Abstract

Junhua Yu¹,Sungmoon Choi¹

Seoul National Univ¹

Stable luminescent silver clusters, named as silver nanodots (AgNDs), have been successfully encapsulated in several scaffolds, such as dendrimers, 1 microgels, 2 peptides, 3 and single stranded DNA (ssDNA). 4 ssDNA with varying sequences have produced the widest variety of and most robust nanodot emitters with spectrally pure emissions from the blue to near-IR wavelengths. Besides the much better brightness due to the competitive luminescent quantum yield and excellent molar extinction coefficient, silver nanodots exhibit excellent stability, at least 15-fold more photostable than organic dyes, illustrating great potential as a new generation of fluorophores. 5 Silver nanodots are usually generated by reducing a mixture of silver ions and their protective group in solution, followed by the rearrangement of the reduced silver to form luminescent clusters. 6-8 Their characterizations are conducted thereafter or in a polyvinyl alcohol) (PVA) film. However, the generation and activity of silver nanodots on the surface has not been studied well. Surface chemistry plays an important role in determining the functionality of nanomaterials. 9 The interactions between the surface and the reactive molecules on the surface, as well as between these reactive molecules, may influence the reactivity of the surface molecules. Moreover, the stabilization of the silver cluster core in the nanodot is mainly related to coordinated covalent bonding. This indicates that the interactions between the silver cluster and the surrounding ligands are critically important, and therefore, the surface chemistry plays an even more essential role in the stabilization of silver nanodots. Herein, we have investigated the factors that determine the generation of silver nanodots and selectively controlled the spectrum of the silver nanodot. We found that the fundamentals for the generation of silver nanodots on surfaces is different from that in solution.10,11 Adsorbed ssDNA molecules cannot efficiently assist the generation of silver nanodots by either direct chemical reduction or photoactivation. Instead, silver nanodots can be instantly generated on the surface by silver cluster transfer, significantly faster than other methods to generate the same emitter in solution. Contrary to the most easily generated red emitter in solution, the predominant species on the surface is the near-IR emitter. This is likely due to the surface structure that stabilizes the near-IR emitter. Moreover, the kinetic trapping of ssDNA molecules on the surface also limits the reorganization of the resulting silver nanodots for other silver nanodot emitters. Adjusting the freedom of the adsorbed ssDNA on the surface can tune the generation of various silver nanodots on the surface. 1. J. Zheng and R. M. Dickson, J. Am. Chem. Soc., 2002, 124, 13982-13983. 2. J. G. Zhang, S. Q. Xu and E. Kumacheva, Adv. Mater., 2005, 17, 2336-2340. 3. J. Yu, S. A. Patel and R. M. Dickson, Angew. Chem.-Int. Edit., 2007, 46, 2028-2030. 4. J. T. Petty, J. Zheng, N. V. Hud and R. M. Dickson, J. Am. Chem. Soc., 2004, 126, 5207-5212. 5. C. I. Richards, S. Choi, J. C. Hsiang, Y. Antoku, T. Vosch, A. Bongiorno, Y. L. Tzeng and R. M. Dickson, J. Am. Chem. Soc., 2008, 130, 5038-5039. 6. S. Choi, S. Park, K. Lee and J. Yu, Chem. Commun., 2013, 49, 10908-10910. 7. S. Choi, S. Park and J. Yu, Chem. Commun., 2014, 50, 15098-15100. 8. S. Choi, R. M. Dickson and J. Yu, Chem. Soc. Rev., 2012, 41, 1867-1891. 9. A. Verma, O. Uzun, Y. H. Hu, Y. Hu, H. S. Han, N. Watson, S. L. Chen, D. J. Irvine and F. Stellacci, Nat. Mater., 2008, 7, 588-595. 10. Y. Zhao, S. Choi, S. Hong, E. Lee and J. Yu, Advanced Materials Interfaces, n/a, 2201121. 11. S. Hong, Y. Zhao, S. Choi, E. Lee and J. Yu, Chem. Commun., 2022, DOI: 10.1039/D2CC02678C.