Nanochannel FET Biosensor Gate Field Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sensors lack the sensitivity and efficiency to detect chemical and biological species at the nanoscale, particularly in complex samples like blood and saliva, and are not suitable for point-of-care diagnostics or wearable devices.
Innovation Solution
Silicon nanochannel field effect transistor (FET) biosensors with surface-functionalized receptors and gate electrodes that apply electric fields to detect biomolecular binding events, enabling high-sensitivity detection of analytes through conductance changes, and allowing for selective functionalization and parallel detection of multiple species.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensors are used for analyte detection, then device complexity is reduced, but measurement precision and sensitivity are insufficient for nanoscale detection
Solution Approach 1:
The sensor is segmented into distinct functional components: a nanoscale sensing element (nanowire or nanochannel) separate from the bulk device structure. This segmentation allows the sensitive nanoscale region to provide high measurement precision while the larger bulk structure maintains manufacturability and reduces overall device complexity.
Solution Approach 2:
The invention transitions from conventional 2D sensor surfaces to 3D nanoscale structures (nanowires with diameter 1-100 nm, nanochannels with width 1-100 nm). This dimensional change increases the surface-to-volume ratio by orders of magnitude, enabling single-molecule detection sensitivity while maintaining compact device footprints suitable for portable applications.
2Productivity
If sensor arrays are used for parallel detection, then productivity increases, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The sensor array uses identical nanoscale sensing elements (nanowires or nanochannels) that can be selectively functionalized with different receptors. This universal platform approach allows parallel detection of multiple analytes using the same manufacturing process, increasing productivity without proportionally increasing manufacturing complexity.
Solution Approach 2:
While the overall sensor array structure remains uniform for easy manufacturing, local quality is introduced through selective functionalization of specific nanoscale elements with different receptor molecules. This allows each sensor in the array to detect different analytes, enabling parallel multi-analyte detection while maintaining manufacturing simplicity.
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
These sensors achieve single-molecule detection sensitivity, reduce error rates in diagnostics, and enable cost-effective, high-yield manufacturing, suitable for point-of-care and wearable applications, with enhanced sensitivity and reliability for monitoring vital signs and disease markers.
Implementation Method 1
a gate electrode configured to apply an electric field
Implementation Method 2
semiconductor devices, or similar small-scale electrical devices, as sensitive transducers to convert chemical activity of interest into corresponding electrical signals
Data Source
AI summary
A nanoelectric field effect sensor uses the field created by the surface charge profile of biomolecular binding to modulate the current flowing between a source and a drain. We have shown that a patterned side or top gate can be used to calibrate the biomolecular field modulation. This approach provides an electrical sensitivity characterization of the sensor before exposing it to sample fluid. Furthermore, a side gate or a top gate voltage with the right sign can be used to control the binding event during functionalization or sensing. For instance, a negative gate voltage can prevent binding of negatively charged proteins on a sensor. This approach of electric-field control of binding can be used in a differential sensor configuration as well. For instance, in a two-sensor single-bridge technique, one of the sensors can be exposed to a local electric field to prevent binding events, which can then be used for background cancellation in a second sensor, not exposed to the electric field. Furthermore, this approach can be used to prepare a sensor chip for multiplexing, where different chip areas can be turned on or off by applying local electric fields.