In this research field, we are developing single-molecule analytical technologies that probe the electrical conductance, temperature, heat, and structure of individual molecules by using nanodevices fabricated through advanced nanotechnology, thereby pioneering the foundations of single-molecule science. Furthermore, by applying these single-molecule analytical techniques, we are developing single-molecule DNA and RNA sequencers and single-molecule structural analysis methods that will support personalized medicine. Through integrated research spanning from fundamental science to practical applications, we aim to create bio-innovations that contribute to a safe, secure, and healthy society.
Single-Nano Technology
Ultra-fine fabrication technology below 10 nanometers
We are developing technologies that enable the fabrication of extremely fine structures smaller than 10 nanometers (nm). A scale of 10 nanometers corresponds to an unimaginably small world—approximately one ten-thousandth the thickness of a human hair.
Specifically, we focus on the precise fabrication of the following two structures:
Nanogap: a technology for creating gaps of less than 10 nm between electrodes
Nanopore: a technology for drilling extremely small holes with diameters below 10 nm
These ultra-fine structures are fabricated by combining semiconductor manufacturing techniques with electron-beam lithography, a method that uses a focused beam of electrons like a pencil to draw patterns in the microscopic world.
This approach enables us to fabricate structures with identical shapes and sizes in large numbers (high reproducibility) while minimizing defects (high yield). As a result, this technology contributes to the development of next-generation electronic and medical devices that enrich everyday life.
Nanogap
Nanogap
A nanogap is a special type of electrode with an extremely narrow gap—approximately 1 nanometer, which is about one hundred-thousandth the thickness of a human hair. When a voltage is applied across this gap, an extremely weak current known as a tunneling current flows as a result of quantum-mechanical phenomena in the microscopic world. If a small molecule, such as DNA or a nanoparticle, enters this narrow gap, the magnitude of the tunneling current changes depending on the type of molecule.
At the Taniguchi Laboratory, we are leveraging this principle to develop novel technologies capable of detecting and identifying individual biomolecules—such as DNA, RNA, peptides, and neurotransmitters—one molecule at a time.
Nanopore
Nanopore
A nanopore is an extremely small hole with a diameter of several hundred nanometers or less, fabricated in a silicon substrate. When this pore is filled with an electrolyte solution such as potassium chloride (KCl) and a voltage is applied between electrodes placed above and below the pore, a very small ionic current (on the order of nanoamperes) flows.
When a specific substance enters the nanopore, the flow of ions is temporarily obstructed, causing a transient decrease in the current. This change appears as a characteristic current waveform that contains information about the size, structure, and surface charge of the substance.
However, visually distinguishing these waveforms can be extremely challenging, particularly when attempting to discriminate between substances of similar size. To address this challenge, we employ artificial intelligence (AI). By training AI models on large numbers of waveforms, it becomes possible to identify substances with high accuracy based on subtle differences in the signals that are imperceptible to the human eye.
At the Taniguchi Laboratory, we are developing nanopores tailored to specific targets and applying this technology to research aimed at identifying viruses and bacteria one by one.