The latest in the nano-revolution has been developed by researchers at the University of Illinois. Their 'nanoneedle' will help examine the biological processes occurring within living cells.
"Nanoneedle-based delivery is a powerful new tool for studying biological processes and biophysical properties at the molecular level inside living cells," said Min-Feng Yu, a professor of mechanical science and engineering and corresponding author.
During the study, he described how they deliver, detect and track individual fluorescent quantum dots in a cell's cytoplasm and nucleus.
These quantum dots can be used for studying molecular mechanics and physical properties inside cells.
To create a nanoneedle, the researchers begin with a rigid but resilient boron-nitride nanotube. The nanotube is then attached to one end of a glass pipette for easy handling, and coated with a thin layer of gold.
The molecular cargo is then attached to the gold surface via "linker" molecules.
When placed in a cell's cytoplasm or nucleus, the bonds with the linker molecules break, freeing the cargo.
"The nanoneedle provides a mechanism by which we can quantitatively examine biological processes occurring within a cell's nucleus or cytoplasm," said Yang Xiang, a professor of molecular and integrative physiology and a co-author of the paper.
"By studying how individual proteins and molecules of DNA or RNA mobilize, we can better understand how the system functions as a whole," Xiang added.
The ability to deliver a small number of molecules or nanoparticles into living cells with spatial and temporal precision may make feasible numerous new strategies for biological studies at the single-molecule level, which would otherwise be technically challenging or even impossible.
"Combined with molecular targeting strategies using quantum dots and magnetic nanoparticles as molecular probes, the nanoneedle delivery method can potentially enable the simultaneous observation and manipulation of individual molecules," said Ning Wang, a professor of mechanical science and engineering and a co-author of the paper.
"Nanoneedles can be used as electrochemical probes and as optical biosensors to study cellular environments, stimulate certain types of biological sequences, and examine the effect of nanoparticles on cellular physiology," said Yu.
The study appears in Nano Letters