Longitudinally Displaced Nanoscale Electrodes for Voltage Sensing
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Solution Overview
Problem
Current biopolymer sequencing techniques, such as Coulter counting, face challenges in decoupling the electrophoretic force from the measurement signal, leading to suboptimal conditions for DNA translocation and analysis, particularly in nanoscale applications.
Innovation Solution
The use of longitudinally displaced electrodes for electronic sensing in fluidic channels allows for the determination of biopolymer length and probe distances by monitoring voltage changes as DNA fragments pass through, decoupling the measurement from the translocation force and enabling precise characterization of nanoscale analytes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transverse electrodes are used to generate electric current for sensing biomolecules, then measurement capability is provided, but electrode degradation occurs
Solution Approach 1:
The electrode system is divided into two distinct functional components: transverse sensing electrodes for voltage measurement and longitudinal electromotive electrodes for current generation. This segmentation allows each electrode type to be optimized for its specific function, preventing the degradation issues that arise when electrodes attempt to perform both sensing and driving functions simultaneously.
Solution Approach 2:
The patent combines transverse sensing electrodes and longitudinal electromotive electrodes into a single integrated device structure. This merging allows the system to achieve both high-precision voltage sensing and effective electrophoretic driving without the trade-offs of separate systems, as the longitudinal electrodes provide stable current while the transverse electrodes perform non-invasive voltage measurements.
2Device complexity
If the same electrodes are used for both translocation driving and measurement, then device complexity is reduced, but measurement precision deteriorates due to coupled effects
Solution Approach 1:
The electrode system is divided into two distinct functional components: transverse sensing electrodes for voltage measurement and longitudinal electromotive electrodes for current generation. This segmentation allows each electrode type to be optimized for its specific function, preventing the degradation issues that arise when electrodes attempt to perform both sensing and driving functions simultaneously.
3Speed
If DC voltage is applied for DNA translocation, then physical translocation is achieved, but the measurement signal is inseparably coupled to the driving force
Solution Approach 1:
The electrode system is divided into two distinct functional components: transverse sensing electrodes for voltage measurement and longitudinal electromotive electrodes for current generation. This segmentation allows each electrode type to be optimized for its specific function, preventing the degradation issues that arise when electrodes attempt to perform both sensing and driving functions simultaneously.
Solution Approach 2:
The patent introduces an intermediary measurement approach by using transverse electrodes to measure voltage drop across the nanochannel rather than measuring current directly through the driving electrodes. This intermediary voltage measurement is then related to analyte properties through the known relationship between voltage, current, and resistance, decoupling the measurement from the driving force.
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
This approach enables accurate measurement of biopolymer length and probe distances, improving the sensitivity and precision of DNA analysis while reducing electrode degradation, and allowing for the detection of single molecules in nanoscale fluidic channels.
Implementation Method 1
the fluidic channel contains only the ionic solution and typically have a baseline potential difference measured between the two sensing electrodes. As DNA enters the fluidic channel, the potential measured between the two sensing electrodes may change because the DNA has a conductivity different from that of the ionic solution.
Implementation Method 2
Macroscopic electrodes may be connected to a power supply and used to apply a potential between the two reservoirs. DNA fragments may be electrophoretically driven from the microscopic reservoir into the nanochannels.
Data Source
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AI summary
Devices and methods for detecting an analyte are provided. Devices (100) for voltage sensing of analytes may comprise a fluidic channel (105) defined in a substrate, a pair of sensing electrodes (115A, 115B) disposed in a fluidic channel for sensing voltage therein, and a pair of electromotive electrodes (110, 110') for applying potential along the fluidic channel. The pair of sensing electrodes may include a first and second sensing electrode disposed at two discrete locations along the length of the fluidic channel and the pair of electromotive electrodes may be disposed at a first end and a second end of the fluidic channel. The fluidic channel may include a nanochannel or a microchannel. Methods for detecting an analyte may include the steps of disposing the analyte in a fluidic channel; applying a potential along the fluidic channel to generate an electrophoretic force therein such that the analyte is translocated from a first end of the fluidic channel to a second end of the fluidic channel; and measuring a voltage signal between a pair of sensing electrodes disposed in the fluidic channel as the analyte moves past the sensing electrodes.