Reversible photo- and thermal-effects on the luminescence of gold nanoclusters: implications for nanothermometry

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F21%3A00543095" target="_blank" >RIV/61388963:_____/21:00543095 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11110/21:10429875 RIV/00216208:11320/21:10429875

Výsledek na webu

<a href="https://doi.org/10.1039/D0CP06467J" target="_blank" >https://doi.org/10.1039/D0CP06467J</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d0cp06467j" target="_blank" >10.1039/d0cp06467j</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Reversible photo- and thermal-effects on the luminescence of gold nanoclusters: implications for nanothermometry

Popis výsledku v původním jazyce

The optical properties of colloidal near-infrared (NIR) emitting gold nanoclusters (AuNCs) are thoroughly investigated at variable temperatures and excitation powers. Both absorption and photoluminescence (PL) excitation spectra reveal optical transitions expected from literature models of thiolated AuNCs – with the exception of the lowest energy transition which has the form of a featureless absorption tail partially overlapping with the PL band. The absorption cross section is determined via the PL saturation and PL modulation techniques to be in the range of 2–3 × 10−14 cm2 for excitation at 405 nm (relatively large value for such small clusters) and decreases ∼20 times toward 633 nm. Slow transient quenching (perfectly reversible) of PL is observed when the excitation power exceeds the saturation threshold, i.e. when the probability of achieving the second absorption in an excited AuNC before its relaxation is significant. A stable PL quenched level is reached within a fraction of a minute or a few minutes after the start of the excitation. Similar time intervals are needed for AuNCs to relax back to the original state in the dark. By comparing thermally-induced and light-induced PL decreases and PL kinetics speed up, we conclude that the transient quenching is due to heating caused by the dissipated excitation power. The light-induced PL amplitude reduction is much stronger (up to ∼80% under 405 nm, 60 W cm−2 excitation) than changes in PL decay time (∼20%), which is due to PL blinking and PL switching-off in a fraction of the AuNC ensemble. The potential application of these AuNCs in nanothermometry is discussed.

Název v anglickém jazyce

Reversible photo- and thermal-effects on the luminescence of gold nanoclusters: implications for nanothermometry

Popis výsledku anglicky

The optical properties of colloidal near-infrared (NIR) emitting gold nanoclusters (AuNCs) are thoroughly investigated at variable temperatures and excitation powers. Both absorption and photoluminescence (PL) excitation spectra reveal optical transitions expected from literature models of thiolated AuNCs – with the exception of the lowest energy transition which has the form of a featureless absorption tail partially overlapping with the PL band. The absorption cross section is determined via the PL saturation and PL modulation techniques to be in the range of 2–3 × 10−14 cm2 for excitation at 405 nm (relatively large value for such small clusters) and decreases ∼20 times toward 633 nm. Slow transient quenching (perfectly reversible) of PL is observed when the excitation power exceeds the saturation threshold, i.e. when the probability of achieving the second absorption in an excited AuNC before its relaxation is significant. A stable PL quenched level is reached within a fraction of a minute or a few minutes after the start of the excitation. Similar time intervals are needed for AuNCs to relax back to the original state in the dark. By comparing thermally-induced and light-induced PL decreases and PL kinetics speed up, we conclude that the transient quenching is due to heating caused by the dissipated excitation power. The light-induced PL amplitude reduction is much stronger (up to ∼80% under 405 nm, 60 W cm−2 excitation) than changes in PL decay time (∼20%), which is due to PL blinking and PL switching-off in a fraction of the AuNC ensemble. The potential application of these AuNCs in nanothermometry is discussed.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)

Projekt

<a href="/cs/project/GA18-12533S" target="_blank" >GA18-12533S: Fluorescenční zlaté nanoklastry a jejich programovatelná skladba pomocí DNA</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

1463-9084

Svazek periodika

23

Číslo periodika v rámci svazku

20

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

7

Strana od-do

11954-11960

Kód UT WoS článku

000651418200001

EID výsledku v databázi Scopus

2-s2.0-85106970711