Different
kinds of nanobarcodes can form a “library†for future nanoscale sensing
applications.
Courtesy: University of Technology Sydney.
Using
barcodes to label and identify everyday items is as familiar as a trip to the
supermarket. Imagine shrinking those barcodes a million times, from millimeter
to nanometre scale, so that they could be used inside living cells to label,
identify and track the building blocks of life or, blended into inks to prevent
counterfeiting. This is the frontier of nanoengineering, requiring fabrication
and controlled manipulation of nanostructures at atomic level—new, fundamental
research, published in Nature Communications, shows the possibilities and
opportunities ahead.
The
University of Technology Sydney (UTS) led collaboration developed a nanocrystal
growth method that controls the growth direction, producing programmable atomic
thin layers, arbitrary barcoded nanorods, with morphology uniformity. The
result is millions of different kinds of nanobarcodes that can form a
"library" for future nanoscale sensing applications.
The
researchers anticipate that such barcode structures will attract broad
interests in a range of applications as information nanocarriers for
bio-nanotechnology, life sciences, data storage, once they are incorporated
into a variety of matrixes.
Lead
author Dr. Shihui Wen said the research provides a benchmark that will open up
the potential for engineering smaller nanophotonics devices.
"The
inorganic nanobarcode structures are rigid, and it is easy to control the
composite, thickness and distance accuracy between different functional
segments for geometrical barcoding beyond the optical diffraction limit.
Because they are chemically and optically stable, the nanoscopic barcodes can
be used as carriers for drug delivery and tracking into the cell, once the
surface of the barcode structures is further modified and functionalized with
probe molecules and cargos," Dr. Wen, from the UTS Institute of Biomedical
Materials and Devices (IBMD), said.
The team
also had an additional breakthrough with the development of a novel, tandem
decoding system, using super-resolution nanoscopy to characterize different
optical barcodes within the diffraction limit.
Senior
author, UTS IBMD Director, Professor Dayong Jin said there was no commercial
system available for this type of super resolution imaging.
"We
had to build the instrumentation to diagnose the sophisticated functions that
can be intentionally built into the tiny nanorod. These together allow us to
unlock the further potential for placing atomic molecules where we want them so
we can continue to miniaturize devices. This was the first time we were able to
use super resolution system to probe, activate and readout the specific
functional segment within the nanorod.
"Imagine
a tiny device, smaller than one thousandth the width of a human hair, and we
can selectively activate a particular region of that device, see the optical
properties, quantify them. This is the science now showing many new possibilities,"
he said. Professor Jin is also the co-director of UTS-SUStech Joint Research
Centre.
The
researchers envisage the developed nanoscale optical devices could be
simultaneously used for tagging different cellular species.
"These
devices are also readily applicable for high-security-level anticounterfeiting
when different batches of them are blended with inks and can be readily printed
on high-value products for authentication." Dr. Wen said.