Unique Energy Transfer in Fluorescein-Conjugated Au22 Nanoclusters Leading to 160-Fold pH-Contrasting Photoluminescence

Kyunglim Pyo, Nguyen Hoang Ly, Sang Myeong Han, Mohammad Bin Hatshan, Abubkr Abuhagr, Gary Wiederrecht, Sang Woo Joo, Guda Ramakrishna, Dongil Lee

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Accurate measurements of intracellular pH are of crucial importance in understanding the cellular activities and in the development of intracellular drug delivery systems. Here we report a highly sensitive pH probe based on a fluorescein-conjugated Au22 nanocluster. Steady-state photoluminescence (PL) measurements have shown that, when conjugated to Au22, fluorescein exhibits more than 160-fold pH-contrasting PL in the pH range of 4.3-7.8. Transient absorption measurements show that there are two competing ultrafast processes in the fluorescein-conjugated Au22 nanocluster: the intracore-state relaxation and the energy transfer from the nonthermalized states of Au22 to fluorescein. The latter becomes predominant at a higher pH, leading to dramatic PL enhancement of fluorescein. In addition to the intrinsically low toxicity, fluorescein-conjugated Au22 nanoclusters exhibit high pH sensitivity, wide dynamic range, and excellent photostability, providing a powerful tool for the study of intracellular processes.

Original languageEnglish
Pages (from-to)5303-5310
Number of pages8
JournalJournal of Physical Chemistry Letters
Volume9
Issue number18
DOIs
Publication statusPublished - 2018 Sep 20

Fingerprint

Nanoclusters
nanoclusters
Fluorescein
Energy transfer
Photoluminescence
energy transfer
photoluminescence
Toxicity
toxicity
dynamic range
delivery
drugs
augmentation
probes
sensitivity

All Science Journal Classification (ASJC) codes

  • Materials Science(all)

Cite this

Pyo, Kyunglim ; Ly, Nguyen Hoang ; Han, Sang Myeong ; Hatshan, Mohammad Bin ; Abuhagr, Abubkr ; Wiederrecht, Gary ; Joo, Sang Woo ; Ramakrishna, Guda ; Lee, Dongil. / Unique Energy Transfer in Fluorescein-Conjugated Au22 Nanoclusters Leading to 160-Fold pH-Contrasting Photoluminescence. In: Journal of Physical Chemistry Letters. 2018 ; Vol. 9, No. 18. pp. 5303-5310.
@article{7796d2f594a64369b53e9a2210805889,
title = "Unique Energy Transfer in Fluorescein-Conjugated Au22 Nanoclusters Leading to 160-Fold pH-Contrasting Photoluminescence",
abstract = "Accurate measurements of intracellular pH are of crucial importance in understanding the cellular activities and in the development of intracellular drug delivery systems. Here we report a highly sensitive pH probe based on a fluorescein-conjugated Au22 nanocluster. Steady-state photoluminescence (PL) measurements have shown that, when conjugated to Au22, fluorescein exhibits more than 160-fold pH-contrasting PL in the pH range of 4.3-7.8. Transient absorption measurements show that there are two competing ultrafast processes in the fluorescein-conjugated Au22 nanocluster: the intracore-state relaxation and the energy transfer from the nonthermalized states of Au22 to fluorescein. The latter becomes predominant at a higher pH, leading to dramatic PL enhancement of fluorescein. In addition to the intrinsically low toxicity, fluorescein-conjugated Au22 nanoclusters exhibit high pH sensitivity, wide dynamic range, and excellent photostability, providing a powerful tool for the study of intracellular processes.",
author = "Kyunglim Pyo and Ly, {Nguyen Hoang} and Han, {Sang Myeong} and Hatshan, {Mohammad Bin} and Abubkr Abuhagr and Gary Wiederrecht and Joo, {Sang Woo} and Guda Ramakrishna and Dongil Lee",
year = "2018",
month = "9",
day = "20",
doi = "10.1021/acs.jpclett.8b02130",
language = "English",
volume = "9",
pages = "5303--5310",
journal = "Journal of Physical Chemistry Letters",
issn = "1948-7185",
publisher = "American Chemical Society",
number = "18",

}

Unique Energy Transfer in Fluorescein-Conjugated Au22 Nanoclusters Leading to 160-Fold pH-Contrasting Photoluminescence. / Pyo, Kyunglim; Ly, Nguyen Hoang; Han, Sang Myeong; Hatshan, Mohammad Bin; Abuhagr, Abubkr; Wiederrecht, Gary; Joo, Sang Woo; Ramakrishna, Guda; Lee, Dongil.

In: Journal of Physical Chemistry Letters, Vol. 9, No. 18, 20.09.2018, p. 5303-5310.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Unique Energy Transfer in Fluorescein-Conjugated Au22 Nanoclusters Leading to 160-Fold pH-Contrasting Photoluminescence

AU - Pyo, Kyunglim

AU - Ly, Nguyen Hoang

AU - Han, Sang Myeong

AU - Hatshan, Mohammad Bin

AU - Abuhagr, Abubkr

AU - Wiederrecht, Gary

AU - Joo, Sang Woo

AU - Ramakrishna, Guda

AU - Lee, Dongil

PY - 2018/9/20

Y1 - 2018/9/20

N2 - Accurate measurements of intracellular pH are of crucial importance in understanding the cellular activities and in the development of intracellular drug delivery systems. Here we report a highly sensitive pH probe based on a fluorescein-conjugated Au22 nanocluster. Steady-state photoluminescence (PL) measurements have shown that, when conjugated to Au22, fluorescein exhibits more than 160-fold pH-contrasting PL in the pH range of 4.3-7.8. Transient absorption measurements show that there are two competing ultrafast processes in the fluorescein-conjugated Au22 nanocluster: the intracore-state relaxation and the energy transfer from the nonthermalized states of Au22 to fluorescein. The latter becomes predominant at a higher pH, leading to dramatic PL enhancement of fluorescein. In addition to the intrinsically low toxicity, fluorescein-conjugated Au22 nanoclusters exhibit high pH sensitivity, wide dynamic range, and excellent photostability, providing a powerful tool for the study of intracellular processes.

AB - Accurate measurements of intracellular pH are of crucial importance in understanding the cellular activities and in the development of intracellular drug delivery systems. Here we report a highly sensitive pH probe based on a fluorescein-conjugated Au22 nanocluster. Steady-state photoluminescence (PL) measurements have shown that, when conjugated to Au22, fluorescein exhibits more than 160-fold pH-contrasting PL in the pH range of 4.3-7.8. Transient absorption measurements show that there are two competing ultrafast processes in the fluorescein-conjugated Au22 nanocluster: the intracore-state relaxation and the energy transfer from the nonthermalized states of Au22 to fluorescein. The latter becomes predominant at a higher pH, leading to dramatic PL enhancement of fluorescein. In addition to the intrinsically low toxicity, fluorescein-conjugated Au22 nanoclusters exhibit high pH sensitivity, wide dynamic range, and excellent photostability, providing a powerful tool for the study of intracellular processes.

UR - http://www.scopus.com/inward/record.url?scp=85053290237&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85053290237&partnerID=8YFLogxK

U2 - 10.1021/acs.jpclett.8b02130

DO - 10.1021/acs.jpclett.8b02130

M3 - Article

AN - SCOPUS:85053290237

VL - 9

SP - 5303

EP - 5310

JO - Journal of Physical Chemistry Letters

JF - Journal of Physical Chemistry Letters

SN - 1948-7185

IS - 18

ER -