# Presentation: 033267

## Solid-state nanopores are nanometer-scale pores in an insulating solid membrane or chip that can be used for rapid electrical detection and characterization of biomolecules.  The solid-state nanopore technology has the potential of becoming the future platform for rapid bio-analysis and DNA sequencing.  The standard nanofabrication techniques such as e-beam lithography and focused ion-beam lithography are incapable of producing sub-10 nanometer pores.  Here, a low-cost method using electrochemical feedback etching is developed which has resulted in nanopores in the range of 1-3 nm.

- A DNA translocation event through a silicon-oxide nanopore device
- fabricated using a table-top feedback etching technique.  Insets: two TEM photos showing two nanopore devices, each containing two nanometer-scale pores in a silicon chip (after oxidation).

**Notes:**
One of the grand challenges in genomics research is to develop a DNA sequencing technology costing no more than $1k per human genome.  Such “personal genomics” technology will greatly advance the science of molecular biology and medicine.  It has been proposed that solid-state nanopores, with proper features, can be used for rapid DNA sequencing.  A desired nanopore should have a diameter around 1.5-5 nm so that a DNA molecule will be translocated in a linear fashion under the drive of a voltage.  It should also be as short as possible, ideally around 1nm, so that few bases reside in the pore at any given time.  This requirement poses a great technical challenge for solid-state physicists since standard nanofabrication techniques such as electron-beam lithography and focused ion-beam lithography are incapable of producing such fine features.  During the last few years, two promising techniques, ion-beam sculpting and electron-beam heating, have been developed.  However, these techniques are still too expensive as they require special ion-beam system or extensive usage of transmission electron microscope.  Here a low-cost table-top nanofabrication technique has been developed by the PI’s group at Brown University.  This technique only uses the standard optical lithography followed by an electrochemical feedback etching, and post-etch oxygen annealing.  Nanopores devices ranging from 2nm to 20 nm have been fabricated and used for DNA translocation studies.

## A low-cost nanofabrication method for fabricating silicon nanopores for rapid detection of biomolecules

- One undergraduate student (Adam Politzer) contributed to this program.  Adam is currently a graduate student at UC Berkeley.  Two graduate students Hongbo Peng and Shanshan Wu are carrying out their Ph.D. thesis studies under this program.  Postdoc Sang Ryul Park is a key participant of the project.

**A low-cost nanofabrication method for fabricating silicon nanopores for rapid detection of biomolecules**
**X. S. Ling, Brown University,**  NIRT-0403891

**Societal Impact:**
- Silicon nanopore technology, developed with NIRT support, has the potential of revolutionizing molecular biology and medicine.  This technology is being commercialized and is being further developed for a number of important genomic applications .

**Notes:**
Silicon nanopore technology is being developed using NSF-NIRT support.  The nanopore DNA sequencing technology is one of the most compelling candidates in the international race towards a fully working “$1k DNA sequencing technology”.  

The study of DNA translocation through a solid-state nanopore is also of broad fundamental interest, since a linear flexible polymer translocating through a highly confined space is a prototypical problem in biological systems, and in statistical physics.

Students gain the most advanced knowledge of nanofabrication and molecular biophysics in the course of their research under this project.  

(The picture shows a 10-nanopore device being developed in collaboration with NABsys, Inc. a RI startup company which has the exclusive license to the silicon nanopore technology being developed at Brown.)