Concatemeric Aptamer Biosensors via Non-Chemical Paper Adsorption
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Solution Overview
Problem
Current methods for fabricating paper-based biosensors are laborious, prone to non-specific binding, and costly due to the need for complex chemical modifications or immobilization strategies, which limits their use in point-of-care diagnostics and disease screening, especially for DNA aptamers that require intricate immobilization techniques.
Innovation Solution
The development of biosensors using concatemeric nucleic acid molecules absorbed onto substrates through non-chemical means such as printing and spotting, allowing for direct deposition of structure-switching aptamers onto unmodified paper surfaces, which remain immobilized and functional after liquid flow, enabling effective detection of analytes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemical modification or complex immobilization strategies are used to fabricate paper-based biosensors, then the biosensor functionality and specificity are improved, but the fabrication complexity and cost increase
Solution Approach 1:
The invention extracts the biomolecule immobilization step entirely from the fabrication process by using pre-formed concatemeric nucleic acid structures that self-assemble on the paper substrate through non-specific adsorption, eliminating the need for chemical modification or complex immobilization chemistry while maintaining sensor functionality
Solution Approach 2:
The concatemeric nucleic acid molecules serve themselves by automatically assembling and immobilizing on the paper substrate through their inherent physical properties (size, charge, concentration) without requiring external chemical agents or complex processing steps, thereby simplifying fabrication while preserving biosensor reliability
2Stability of the object's composition
If chemical modification methods are used to immobilize biomolecules on paper, then the biosensor stability is improved, but the non-specific binding increases
Solution Approach 1:
The invention uses a disposable paper substrate approach where the paper itself serves as a single-use platform that provides sufficient mechanical stability without requiring permanent chemical modifications, allowing the sensor to be discarded after one use and eliminating the need for stable chemical bonds that would cause non-specific binding
Solution Approach 2:
The invention changes the immobilization mechanism from chemical bonding to physical adsorption by controlling parameters such as nucleic acid concentration, solution pH, and drying conditions, which provides adequate stability for the assay while avoiding the non-specific binding issues associated with chemical crosslinking
3Measurement precision
If complex conjugation strategies are used for DNA aptamers, then the detection specificity is improved, but the ease of manufacture decreases
Solution Approach 1:
The invention segments the aptamer function from the immobilization requirement by using concatemeric structures where multiple aptamer repeats are connected in tandem, allowing the aptamers to maintain their detection specificity while the entire concatemer serves as the immobilized element on paper, greatly simplifying manufacture
Solution Approach 2:
The concatemeric nucleic acid structures serve multiple functions simultaneously: they provide the aptamer binding sites for specific detection, act as the immobilized element on the paper substrate, and function as the signaling element through their structural changes, eliminating the need for separate conjugation steps
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 simplifies the fabrication of paper-based biosensors, reduces non-specific binding, and enhances the stability and functionality of DNA aptamers, allowing for reliable and cost-effective detection of analytes, particularly in point-of-care diagnostics.
Implementation Method 1
one or more reporter layers absorbed on the substrate by non-chemical means selected from printing and spotting
Implementation Method 2
reporter nucleic acid molecules for detection of the analyte... retain sufficient local and segmental motion required for structure-switching and signaling to occur
Data Source
AI summary
The present application relates to biosensors, for example comprising an high-molecular weight, tandem repeating, structure-switching nucleic acid aptamers (concatemeric aptamers) to rapidly create patterned sensors via, for example, inkjet printing. These concatemeric aptamer reporters remain immobilized at the point of printing through strong adsorption but retain sufficient segmental mobility to undergo structure switching and reporter signalling to provide both qualitative and quantitative detection of one or more analytes. In certain embodiments, inkjet printing allows for the patterning of internally referenced sensors with multiplexed detection, and provides a generic platform for on-demand printing of sensors even in remote locations.