J.Zhou/A single nanoparticle can act like a laser
J.Zhou/A single nanoparticle can act like a laser

Pumping a nanoparticle to lase at low power

Embargoed until: Publicly released:
Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts.

Experimental study: At least one thing in the experiment was changed to see if it had an impact on the subjects (often people or animals) – eg: changing the amount of time mice spend on an exercise wheel to find out what impact it has on weight loss.

A laser pointer small enough to get inside a cancer cell and stop its "engine"? The stuff of science fiction? Scientists working at the nanoscale are chipping away at how to build miniature laser devices capable of intracellular bio-imaging and sensing.

Journal/conference: Nature Communications

Link to research (DOI): 10.1038/s41467-020-19797-4

Organisation/s: University of Technology Sydney (UTS)

Funder: Australian Research Council, National Natural Science Foundation of China, Science and Technology Innovation Commission of Shenzhen, Australia China Science and Research Fund Joint Research Centre for Point-of-Care Testing

Media release

From: University of Technology Sydney (UTS)

Lasers are used in a range of everyday devices, harnessing the power of light molecules, photons, - lined up to form highly concentrated beams of light - to perform now common tasks such as scanning barcodes and removing tattoos.

As biosensing and bio-imaging research seeks to look deep inside tissue to the intracellular level miniaturising laser devices poses significant challenges for these nanoscale biological applications. In new research, published in Nature Communications, scientists demonstrate how the earlier promising concept of a microcavity laser can produce an energy-saving and user-safe laser emissions requiring low pump power.

Corresponding author Dr Jiajia Zhou, from the University of Technology Sydney (UTS), said that normally low pump power is insufficient to make nanoparticles to lase but the team was able to “control the luminescent emitters within every single nanoparticle to interact with each other so that the electrons can accumulate at specific energy levels”.

“This means that even at a very low power pump the nanoparticles will lase, in fact we demonstrated a two-order of magnitude lower pumping threshold compared to what is usually achieved,” she said.

The research team also had to engineer the binding surface of the nanoparticle matrix to form a cavity surface with a uniform single layer.

Dr Zhou said that potentially the Near Infra Red (NIR) microcavity laser can be embedded in thick tissues, single cells, and to sense the environmental indicators such as temperature, pH, and refractive index.

“Monitoring the change of these indicators can tell us the health status of the tissues or cells, which sits in the scope of early-stage disease detection, “she said.

Senior author, director of UTS Institute for Biomedical Materials & Devices Professor Dayong Jin, said this discovery held great promise for biological applications.

‘’I think this is definitely a step forward to realising the dream that just as we use a laser pointer on a powerpoint slide, we could point a tiny device inside a cell, and illuminate an area of interest inside the compartments of a cell.

“Lowering the requirement for the pump power means less tissue damage as the laser penetrates the sample. Also, in this case the laser emission is as sharp as a line, it can sense the indicators more accurately by avoiding the undesired interference which frequently happens in spontaneous fluorescence-based sensing,” he said.

“It’s not science fiction.  We’ve demonstrated a single nanoparticle, which is smaller than an intracellular compartment, can act like a laser, and at low power but it can still emit a sharp signal. In otherwords a ‘laser pointer’ small enough to get inside a cancer cell, and illuminate to stop the engine of that cancer cell,” Professor Jin, who is also the director of UTS-SUStech Joint Research Centre, said.

News for:

Australia
NSW

Media contact details for this story are only visible to registered journalists.