Affinity Sensor Nanoscale Segmentation for Adsorption Density
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Solution Overview
Problem
Existing affinity sensors face challenges in confining adsorption events within nanoscale regions to achieve high signal-to-noise ratios and cater to techniques with large measurement footprints, such as QCM and SPR, due to uncertainties in how nanopatterns affect solute adsorption and the limited availability of sites for adsorption.
Innovation Solution
A binary pattern of nanoscale regions with diameters ranging from 5 to 200 nm, isolated by a passivated region, is used to confine analyte adsorption on an affinity sensor interface, where the nanoscale regions comprise at least 15% of the surface area, allowing for enhanced receptor densities and kinetics of adsorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If nanoscale regions are used to confine adsorption events, then sensitivity and adsorption density are enhanced, but the total surface area available for adsorption is reduced
Solution Approach 1:
The sensor surface is segmented into discrete nanoscale regions (5-200 nm diameter) separated by passivated regions. This segmentation confines adsorption events to specific nanoscale sites, enhancing local adsorption density and sensitivity while the passivated regions prevent non-specific binding. The segmented structure allows the sensor to achieve high measurement precision despite limited total surface area.
Solution Approach 2:
Different regions of the sensor surface are given different properties: nanoscale regions have high affinity for the analyte while passivated regions have low affinity. This local quality differentiation ensures that adsorption occurs preferentially at nanoscale regions, concentrating the adsorbate and enhancing sensitivity. The local quality approach allows maximization of adsorption density within the available surface area.
2Productivity
If nanoscale regions with high receptor density are created, then adsorption kinetics are improved, but the complexity of fabricating the nanopattern increases
Solution Approach 1:
The nanopattern is pre-fabricated on the sensor surface before the analyte is introduced. The nanoscale regions with high receptor density are created in advance through techniques such as colloidal lithography or electron beam lithography, establishing the adsorption sites before the binding event occurs. This preliminary action allows the sensor to achieve fast adsorption kinetics without requiring complex real-time control during operation.
Solution Approach 2:
Colloidal particles or other template structures are used as intermediaries to create the nanopattern. These intermediary elements self-assemble or are deposited to form the nanoscale regions, which then serve as templates for receptor attachment. This intermediary approach simplifies fabrication by using self-assembly or template-directed methods rather than direct nanofabrication of the receptors themselves.
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 significantly enhances adsorption densities and kinetics, achieving adsorbed masses comparable or higher than un-patterned sensors, despite a lesser surface area, and increases sensitivity by confining adsorbate onto nanoscale regions on the surface.
Implementation Method 1
adsorption of the analyte is confined to the nanoscale regions
Data Source
AI summary
An aspect of the invention pertains to an affinity biosensor for sensing an analyte (a biomolecule) in a fluid, comprising an interface for contacting the fluid and adsorption of the analyte. The interface comprises a binary pattern of nanoscale regions having affinity for the analyte and a passivated region. The nanoscale regions are isolated from one another by the passivated region in such a way that adsorption of the analyte on the interface is confined to the nanoscale regions. The nanoscale regions have diameters comprised in the range from 5 to 200 nm. The nanoscale regions have together a surface area amounting to at least 15% of the surface area of the interface. A further aspect of the invention relates to a method of using such a sensor.