SERS DNA Sequencing via Plasmonic Hot Spots
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Solution Overview
Problem
Current DNA sequencing methods face limitations in sequence read length, sensitivity, and run time due to the need for labels, which restrict accurate long-read sequencing and are slow due to the requirement for real-time optical signal acquisition and tag removal.
Innovation Solution
The use of Surface-Enhanced Raman Spectroscopy (SERS) sensors with plasmonic nanostructures to identify individual, unlabeled nucleotides by measuring unique Raman signatures, enabling fast, label-free, and long-read DNA sequencing through a Raman 'hot spot' generated by laser excitation and enhanced by resonance of nanostructures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If labels are used for DNA sequencing, then detection sensitivity is improved, but sequencing run time increases due to real-time optical signal acquisition and tag removal requirements
Solution Approach 1:
The invention extracts and removes the labeling step from the sequencing process entirely. By using SERS to detect the intrinsic vibrational signatures of nucleotides directly, the method eliminates the need for fluorescent labels and their associated timing constraints, thereby reducing run time while maintaining detection sensitivity
Solution Approach 2:
The invention replaces the optical detection system (fluorescence microscopy) with a vibrational spectroscopy system (Raman spectroscopy). This substitution eliminates the need for optical labels and their excitation/detection machinery, enabling faster acquisition without sacrificing sensitivity
2Measurement precision
If labels are used for DNA sequencing, then nucleotide identification is improved, but sequence read length is limited
Solution Approach 1:
The invention removes the labeling requirement entirely, allowing continuous sequencing of long DNA strands without the technical constraints that limit read length in label-based methods. The label-free SERS approach enables accurate identification of nucleotides throughout the entire length of long reads
Solution Approach 2:
The invention performs preliminary enrichment of the Raman signal using SERS enhancement from metallic nanostructures. This preliminary signal amplification occurs before detection, enabling accurate nucleotide identification in label-free conditions and thus supporting longer read lengths
3Productivity
If label-free sequencing is used, then sequencing speed is improved, but detection sensitivity decreases
Solution Approach 1:
The invention replaces fluorescence detection with Raman spectroscopy detection. Since Raman spectroscopy inherently provides molecular fingerprinting without requiring labels, the system achieves both label-free operation (fast sequencing) and sufficient detection sensitivity through the characteristic vibrational signals of nucleotides
Solution Approach 2:
The invention changes the detection parameter from optical absorption/emission (fluorescence) to vibrational energy transitions (Raman scattering). This parameter change enables label-free detection while maintaining sensitivity, as each nucleotide has a unique Raman spectrum that can be detected without labels
4Extent of automation
If fluorescent labels are used, then real-time optical signal acquisition is enabled, but device complexity increases
Solution Approach 1:
The invention extracts and removes the fluorescent labeling system from the sequencing apparatus. This eliminates the need for fluorescent nucleotides, excitation light sources optimized for fluorescence, and filters for specific wavelengths, thereby reducing device complexity while maintaining real-time detection capability through Raman spectroscopy
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 provides highly accurate, fast, and long-read DNA sequencing capabilities, overcoming the limitations of existing methods by enabling real-time, tag-free identification of nucleotides, improving sensitivity and reducing sequencing time.
Implementation Method 1
Surface-Enhanced Raman Spectroscopy (SERS) sensors or devices, and methods of using, to perform accurate, tag-free or label-free, long-read DNA sequencing
Implementation Method 2
a DNA template strand passes through a Raman hot spot generated by laser excitation and enhanced by resonance of plasmonic (e.g., gold) nanostructures
Implementation Method 3
identifying the nucleotides of a first section of the DNA strand present in the channel at a first period in time by a Raman signature
Data Source
AI summary
A Surface-Enhanced Raman Spectroscopy (SERS) device to perform accurate label-free long-read DNA sequencing. A Raman sensor has a hot spot defined by plasmonic nanostructures and excited by at least one laser. An immobilized DNA polymerase can be used to pull a DNA template strand to be sequenced through the hot spot.