Related Experiment Video
Updated: Mar 21, 2026
09:49
An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers
Published on: October 23, 2018
16.6K
NIR Excitation in Atomically Precise Nanoclusters via Two-Photon and Three-Photon Absorption.
Agata Hajda1, Patryk Obstarczyk1, Joanna Olesiak-Bańska1
1Institute of Advanced Materials, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wrocław, Poland.
Accounts of Chemical Research
|March 19, 2026
Summary
Gold nanoclusters offer tunable light emission and multiphoton absorption for advanced bioimaging. Their unique properties enable efficient near-infrared imaging with reduced phototoxicity, paving the way for new biological applications.
Area of Science:
- Noble metal nanoclusters
- Nanoparticle optics
- Bioimaging technologies
Background:
- Gold nanoclusters possess unique optical properties, including tunable photoluminescence across UV to NIR spectrum.
- These nanoclusters exhibit remarkable multiphoton absorption capabilities, excitable in NIR-I and NIR-II ranges.
- Multiphoton microscopy offers superior 3D imaging and reduced phototoxicity compared to traditional methods.
Purpose of the Study:
- To review current knowledge on multiphoton absorption of noble metal nanoclusters.
- To highlight recent advances and challenges in this field.
- To emphasize the potential of nanoclusters in biological near-infrared (NIR) imaging.
Main Methods:
- Review of existing literature on nanocluster multiphoton absorption.
- Analysis of applications in two- and three-photon absorption and NIR emission.
- Discussion of nanocluster properties for biological imaging.
Main Results:
- Gold nanoclusters act as efficient two- and three-photon absorbers.
- Tunable photoluminescence enables versatile NIR emission.
- Nanoclusters demonstrate significant potential for enhanced biological NIR imaging.
Conclusions:
- Multiphoton excitation combined with noble metal nanoclusters is a powerful approach for efficient NIR bioimaging.
- These nanostructures offer advantages for deep-tissue imaging and reduced cellular damage.
- Further research promises expanded applications in biological and medical diagnostics.
Related Concept Videos
01:23Atomic Spectroscopy: Absorption, Emission, and Fluorescence
3.3K
Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...
3.3K
01:23Atomic Nuclei: Nuclear Relaxation Processes
1.4K
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
1.4K
01:14Molecular Spectroscopy: Absorption and Emission
5.3K
Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
5.3K
01:06Nuclear Overhauser Enhancement (NOE)
1.6K
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the nuclear Overhauser enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring spin-active...
1.6K
02:18The Bohr Model
82.8K
Following the work of Ernest Rutherford and his colleagues in the early twentieth century, the picture of atoms consisting of tiny dense nuclei surrounded by lighter and even tinier electrons continually moving about the nucleus was well established. This picture was called the planetary model since it pictured the atom as a miniature “solar system” with the electrons orbiting the nucleus like planets orbiting the sun. The simplest atom is hydrogen, consisting of a single proton as the...
82.8K
01:05Atomic Nuclei: Magnetic Resonance
1.4K
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
1.4K