Mixed Phosphonic Acid Monolayers for Semiconductor Bio-Sensors
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Solution Overview
Problem
Existing bio-sensors face challenges in achieving manufacturability, compatibility with semiconductor processes, and sensitivity for early detection of biomolecules, particularly due to osmotic shocks and non-uniform biomolecule layers.
Innovation Solution
A bio-sensing device incorporating a mixed phosphonic acid monolayer comprising polyethylene glycol and amine or biotin terminated long-chain compounds, which forms selectively on metal oxides, reducing osmotic shocks and enabling uniform biomolecule attachment, compatible with semiconductor fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If amino-propyl triethoxy silane is used as the sensing layer, then the bio-sensor can be fabricated using common materials, but the sensing layer produces osmotic shocks that reduce detection sensitivity
Solution Approach 1:
The patent changes the chemical composition parameters of the sensing layer by replacing amino-propyl triethoxy silane with a mixed monolayer of phosphonic acid compounds (specifically 3-mercaptopropyl phosphonic acid and 11-mercaptoundecanoic acid) on a gold substrate. This parameter change eliminates osmotic shock effects while maintaining manufacturability through standard semiconductor fabrication processes.
Solution Approach 2:
The patent employs a composite sensing layer structure consisting of a mixed self-assembled monolayer of two different phosphonic acid compounds on a gold substrate. This composite material approach creates a sensing layer that provides both mechanical stability and biochemical compatibility, eliminating osmotic shocks while enabling sensitive detection.
2Adaptability or versatility
If the sensing layer is deposited after semiconductor fabrication, then the bio-sensor can be customized for different analytes, but the process requires shipping to another facility increasing complexity
Solution Approach 1:
The patent incorporates the sensing layer formation as a preliminary step within the semiconductor fabrication process itself, using self-assembled monolayer formation that can be performed in-situ before device assembly. This eliminates the need for post-fabrication shipping and external customization facilities, reducing process complexity while maintaining adaptability.
Solution Approach 2:
The patent creates a universal sensing platform using phosphonic acid monolayers on gold that can detect multiple types of analytes through appropriate biomolecule selection. The standardized gold-phosphonic acid interface provides a universal base that works with various biomolecules (antibodies, aptamers, enzymes), eliminating the need for facility-specific customization while maintaining versatility.
3Measurement precision
If a uniform biomolecule layer is formed, then detection sensitivity increases for early diagnosis, but achieving uniformity requires precise control of functional group modification
Solution Approach 1:
The patent employs self-assembled monolayer formation where the phosphonic acid compounds automatically organize into uniform layers on the gold substrate through spontaneous self-assembly. This self-service mechanism eliminates the need for precise external control of functional group modification, achieving uniform biomolecule attachment while simplifying manufacturing precision requirements.
Solution Approach 2:
The patent uses phosphonic acid compounds as intermediary molecules that self-assemble on the gold substrate to create a uniform platform for biomolecule attachment. These intermediary molecules provide consistent spacing and orientation, ensuring uniform biomolecule distribution without requiring precise control of the attachment process itself, thereby enabling sensitive detection with simplified manufacturing.
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
The solution enhances manufacturability, increases detection sensitivity, and allows for early diagnosis by providing a uniform biomolecule layer that is compatible with semiconductor processes.
Implementation Method 1
a mixed layer on the metal oxide layer but not on the isolation region
Implementation Method 2
PEG molecules advantageously provide the technical benefit of reducing osmotic shocks by keeping water through hydrogen bonding with it
Data Source
AI summary
A semiconductor device-based sensing platform including a substrate, a source/drain region on the substrate, a channel region between the source/drain region, a metal oxide layer on the channel region, an isolation region adjacent the source/drain and channel regions, and a mixed layer on the metal oxide layer but not on the isolation region, wherein the mixed layer comprises a phosphonic acid of polyethylene glycol and at least one phosphonic acid of an amine terminated long-chain compound, and a biotin terminated compound.