Aggregation-Enhanced Photoluminescence and Photoacoustics of Atomically Precise Gold Nanoclusters in Lipid Nanodiscs (NANO2)

Armin Tahmasbi Rad; Yue Bao; Hyun-Sook Jang; Yan Xia; Hari Sharma; Elena E Dormidontova; Jing Zhao; Jaspreet Arora; Vijay T John; Ben Zhong Tang; Tiziano Dainese; Ali Hariri; Jesse V Jokerst; Flavio Maran; Mu-Ping Nieh

doi:10.1002/adfm.202009750

Aggregation-Enhanced Photoluminescence and Photoacoustics of Atomically Precise Gold Nanoclusters in Lipid Nanodiscs (NANO²)

Adv Funct Mater. 2021 Mar 3;31(10):2009750. doi: 10.1002/adfm.202009750. Epub 2020 Dec 13.

Authors

Armin Tahmasbi Rad¹, Yue Bao², Hyun-Sook Jang³, Yan Xia⁴, Hari Sharma⁵, Elena E Dormidontova⁶, Jing Zhao⁷, Jaspreet Arora⁸, Vijay T John⁸, Ben Zhong Tang⁹, Tiziano Dainese¹⁰, Ali Hariri¹¹, Jesse V Jokerst¹¹, Flavio Maran¹², Mu-Ping Nieh¹³

Affiliations

¹ Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA; Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA.
² Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA.
³ Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA; Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea.
⁴ Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA.
⁵ Department of Physics, University of Connecticut, Storrs, CT 06269, USA.
⁶ Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA; Department of Physics, University of Connecticut, Storrs, CT 06269, USA.
⁷ Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA.
⁸ Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA 70118, USA.
⁹ Department of Chemistry, the Hong Kong University of Science and Technology, Hong Kong, P. R. China.
¹⁰ Department of Chemistry, University of Padova, Padova 35131, Italy.
¹¹ Department of NanoEngineering, University of California San Diego, La Jolla, CA 92093, USA.
¹² Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA, Department of Chemistry, University of Padova, Padova 35131, Italy.
¹³ Department of Biomedical Engineering, University of Connecticut Storrs, CT 06269, USA; Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA; Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA.

Abstract

The authors designed a structurally stable nano-in-nano (NANO²) system highly capable of bioimaging via an aggregation-enhanced NIR excited emission and photoacoustic response achieved based on atomically precise gold nanoclusters protected by linear thiolated ligands [Au₂₅(SC _n H_2n+1)₁₈, n = 4-16] encapsulated in discoidal phospholipid bicelles through a one-pot synthesis. The detailed morphological characterization of NANO² is conducted using cryogenic transmission electron microscopy, small/wide angle X-ray scattering with the support of molecular dynamics simulations, providing information on the location of Au nanoclusters in NANO². The photoluminescence observed for NANO² is 20-60 times more intense than that of the free Au nanoclusters, with both excitation and emission wavelengths in the near-infrared range, and the photoacoustic signal is more than tripled. The authors attribute this newly discovered aggregation-enhanced photoluminescence and photoacoustic signals to the restriction of intramolecular motion of the clusters' ligands. With the advantages of biocompatibility and high cellular uptake, NANO² is potentially applicable for both in vitro and in vivo imaging, as the authors demonstrate with NIR excited emission from in vitro A549 human lung and the KB human cervical cancer cells.

Keywords: aggregation-enhanced emission; aggregation-enhanced photoacoustic; bicelles; bioimaging; cellular endocytosis; gold nanocluster.

Grants and funding

S10 OD021821/OD/NIH HHS/United States