Sub-nanometer Electrode Gap DNA Sequencing via Tunneling Current
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Solution Overview
Problem
Current DNA sequencing methods face challenges in fabricating a device with a sub-nanometer electrode gap for accurate and efficient single-molecule DNA sequencing, as existing methods are costly and slow, and conventional MEMS and nanofabrication techniques are inadequate for creating the required structures.
Innovation Solution
The development of DNA sequencing devices with confined nanopores or nanochannels and embedded electrodes, utilizing sub-nanometer fabrication techniques to create an electrode gap of less than 10 nm, allowing for precise measurement of individual nucleotides through transverse tunneling current measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional MEMS and nanofabrication techniques are used to fabricate sub-nanometer electrode gap, then manufacturing capability is insufficient, but the required sequencing accuracy cannot be achieved
Solution Approach 1:
The fabrication process is divided into multiple sequential steps: forming the nanopore structure, depositing sacrificial material, forming electrodes, and removing sacrificial material. This segmentation allows precise control of the electrode gap through intermediate steps, achieving sub-nanometer precision that would be impossible in a single conventional fabrication process.
Solution Approach 2:
Sacrificial material is introduced as an intermediary substance to define the electrode gap geometry during fabrication. This intermediary allows the formation of sub-nanometer gaps by controlling the removal of the sacrificial material, enabling precise electrode positioning that conventional techniques cannot achieve directly.
2Productivity
If existing DNA sequencing methods are used, then current sequencing rates are achieved, but the process is costly and slow
Solution Approach 1:
The patent replaces conventional mechanical and chemical sequencing methods with direct electrical measurement through transverse tunneling current. This substitution eliminates the need for PCR amplification and chemical labeling steps, enabling rapid single-molecule sequencing at orders of magnitude faster rates while reducing costs.
Solution Approach 2:
The invention changes the measurement parameter from indirect optical or chemical signals to direct electrical tunneling current measurements. This parameter change enables real-time detection of individual nucleotides as they pass through the nanopore, dramatically increasing sequencing speed and reducing the time required for complete sequencing.
3Measurement precision
If sub-nanometer electrode gap is created, then single-molecule DNA sequencing accuracy is improved, but fabrication complexity increases
Solution Approach 1:
The nanopore structure and electrode gap are merged into a single integrated fabrication process sequence. The sacrificial material serves dual purposes: defining both the nanopore geometry and the electrode gap geometry. This merging reduces device complexity by eliminating the need for separate precision alignment and positioning systems.
Solution Approach 2:
The sacrificial material performs multiple functions: it defines the nanopore structure, establishes the electrode gap geometry, and serves as a template for electrode positioning. This multi-functionality simplifies the overall device structure by reducing the number of separate components and alignment requirements needed to achieve sub-nanometer precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables direct, rapid, and cost-effective sequencing of DNA strands with high resolution, potentially achieving orders of magnitude faster sequencing rates than current methods, without the need for PCR amplification or chemical labeling.
Implementation Method 1
measuring transverse tunneling current measurement
Data Source
AI summary
Apparatus and methods to sequence DNA. A DNA sequencing device includes a passage, a first electrode, and a second electrode. The passage has a width and a length. The first and second electrodes are exposed within the passage and spaced apart from each other to form an electrode gap. The electrode gap is no greater than about 2 nm. The DNA sequencing device is operable to measure with the first and second electrodes a change in electronic signal in response to nucleotides of a DNA strand passing through the electrode gap.