Nanoscopic barcodes set a new scientific limit

Using barcodes to label and identify everyday items is as familiar as a trip to the supermarket. Imagine reducing those barcodes a million times, from millimeter to nanoscale, so that they can be used inside living cells to label, identify and track the building blocks of life or, mixed in inks to prevent counterfeiting. This is the frontier of nanoengineering, which requires the fabrication and controlled manipulation of nanostructures at the atomic level: new fundamental research, published in Nature Communications, shows future possibilities and opportunities.

The collaboration led by the University of Technology Sydney (UTS) has developed a nanocrystal growth method that controls the direction of growth, producing programmable atomic thin layers, arbitrary barcoded nanodules, with morphological uniformity. The result is millions of different types of nanocodes that can form a “library” for future nano-scale sensing applications.

Researchers predict that such barcode structures will attract broad interest in a range of applications such as information nanocarters for bio-nanotechnology, life sciences, data storage once they are incorporated into a variety of matrices.

Lead author Dr Shihui Wen said the research provides a benchmark that will open up the potential for engineering smaller nanophotonic devices.

“The structures of the inorganic nanobarodes are rigid and it is easy to control the composite, the thickness and the accuracy of the distance between the different functional segments for the geometric coding of the barcodes beyond the limit of optical diffraction. Since they are chemically and optically stable, the Nanoscopic barcodes can be used as aids for drug delivery and monitoring in the cell, once the surface of the barcode structures has been further modified and functionalized with probe and charged molecules, “said Dr. Wen. UTS Institute of Biomedical Materials and Devices (IBMD).

The team also went a step further with the development of a new 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. Together, these allow us to unlock the further potential to place atomic molecules where we want, so that we can continue miniaturizing devices. it was the first time we were able to use the super resolution system to probe, activate and read the specific functional segment within the nanorod.

“Imagine a tiny device, smaller than a thousandth of 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 that now shows many new possibilities,” he said. . . Professor Jin is also the co-director of the UTS-SUStech Joint Research Center.

The researchers predict that the developed nano-scale optical devices could be used simultaneously to label different cell species.

“These devices are also readily applicable for high security anti-counterfeiting when several batches of them are mixed with inks and can be easily printed on high value products for authentication.” Dr. Wen said.