Plasmonic Biosensor with SAM Passivation for Direct Blood Detection
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Solution Overview
Problem
Current methods for detecting viral infections, such as Dengue virus, are slow, costly, and require extensive sample preparation, limiting their applicability beyond commercial laboratories, and existing biosensors face challenges in detecting biomarkers directly from minimally processed biological samples due to non-specific protein binding and protein fouling.
Innovation Solution
A plasmonic biosensor integrated with a microfluidic blood plasma separator, functionalized with high-affinity single-stranded DNA aptamers and a self-assembled monolayer for surface passivation, which detects the Dengue virus NS1 protein directly from blood using localized surface plasmon resonance, reducing non-specific binding and enabling detection at clinically relevant concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If biosensors are used to detect viral biomarkers, then detection speed and accessibility are improved, but non-specific protein binding and protein fouling occur reducing detection accuracy
Solution Approach 1:
The patent introduces a self-assembled monolayer (SAM) as an intermediary passivation layer on the biosensor surface. This SAM layer selectively blocks non-specific protein binding sites while leaving the aptamer binding sites accessible, thereby eliminating protein fouling effects and improving measurement precision without sacrificing detection speed
Solution Approach 2:
The patent modifies the surface chemistry parameters of the biosensor by controlling the composition and structure of the self-assembled monolayer. By adjusting the SAM layer properties (such as chain length, functional groups, and packing density), the sensor achieves optimal balance between preventing non-specific binding and maintaining specific biomarker detection capability
2Measurement precision
If complex sample preparation is performed to remove non-specific proteins, then detection accuracy is improved, but sample processing time and device complexity increase
Solution Approach 1:
The patent applies passivation layer formation as a preliminary action during biosensor fabrication. The self-assembled monolayer is formed on the sensor surface before sample introduction, pre-blocking non-specific binding sites. This eliminates the need for complex sample preparation steps to remove interfering proteins, thereby reducing device complexity while maintaining detection accuracy
3Measurement precision
If high-affinity ssDNA aptamers are used for biomarker binding, then detection sensitivity is improved, but non-specific binding from blood proteins increases
Solution Approach 1:
The patent applies local quality differentiation by creating distinct functional zones on the biosensor surface. The self-assembled monolayer provides non-specific regions that block protein fouling, while aptamer-functionalized regions provide specific high-affinity binding sites. This spatial differentiation allows the sensor to maintain high detection sensitivity while eliminating non-specific binding interference from blood proteins
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 biosensor effectively detects the Dengue virus NS1 protein at concentrations relevant for predicting high-risk infections, achieving rapid and accurate diagnosis directly from blood samples, with potential for broader application in viral infection detection and point-of-care diagnostics.
Implementation Method 1
detecting the biomarker in the sample of blood based upon a localized surface plasmon resonance (LSPR) altering a reflected optical signal from the plasmonic array biosensor
Data Source
AI summary
A method is for detecting a biomarker within a sample of blood. The method may include processing the sample of blood with a microfluidic blood plasma separator and a plasmonic array biosensor, and flowing the sample of blood over a sensing surface of the plasmonic array biosensor. The sensing surface of the plasmonic array biosensor may have an ssDNA aptamer against the biomarker. The method may further include binding the biomarker in the sample of blood to the ssDNA aptamer of the plasmonic array biosensor, and detecting the biomarker in the sample of blood based upon LSPR altering a reflected optical signal from the plasmonic array biosensor.