Stanford study is the first to demonstrate that sophisticated, engineered light resonators can be inserted inside cells without damaging the host. The researchers say it marks a new age in which tiny lasers and light-emitting diodes yield new avenues in the study and influence of living cells.
The researchers call their device a “nanobeam,” because it resembles a steel I-beam with a series of round holes etched through the center. These beams, however, are not massive, but measure only a few microns in length and just a few hundred nanometers in width and thickness. It looks a bit like a piece from an erector set of old. The holes through the beams act like a nanoscale hall of mirrors, focusing and amplifying light at the center of the beam in what are known as photonic cavities. These are the building blocks for nanoscale lasers and LEDs.
At the cellular level, a nanobeam acts like a needle able to penetrate cell walls without injury. Once inserted, the beam emits light, yielding a remarkable array of research applications and implications. While other groups have shown that it is possible to insert simple nanotubes and electrical nanowires into cells, nobody had yet realized such complicated optical components inside biological cells.
In this case, the studied cells came from a prostate tumor, indicating possible application for the probe in cancer research. The primary and most immediate use would be in the real-time sensing of specific proteins within the cells, but the probe could be adapted to sense any important biomolecules such as DNA or RNA.
To detect these key molecules, researchers coat the probe with certain organic molecules or antibodies that are known to attract the target proteins, just like iron to a magnet. If the desired proteins are present within the cell, they begin to accumulate on the probe and cause a slight-but-detectable shift in the wavelength of the light being emitted from the device. This shift is a positive indication that the protein is present and in what quantity.
As such, embeddable nanoscale optical sensors would represent a key development in the quest for patient-specific cancer therapies—often referred to as personalized medicine—in which drugs are targeted to the patient based on efficacy.
This story is reprinted from material from Stanford University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.