Detection units and methods for detecting a target analyte
Inventors
Assignees
Publication Number
US-9382580-B2
Publication Date
2016-07-05
Expiration Date
2032-10-10
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Abstract
Detection units and methods for detecting one or more target analytes in a sample are disclosed. The detection unit provides a first and second surface connected by a filament which is capable of binding the target analyte in the sample. The methods provide for the detection of the target analyte through the generation of a detectable signal following the binding of the target analyte to the filament.
Core Innovation
The invention relates to detection units and methods for the detection of target analytes, such as nucleic acids or proteins, in a sample for diagnostic purposes. The detection unit comprises a first and second surface connected by at least one filament, which includes at least two strands and an active segment capable of binding the target analyte. Binding of the target analyte to the filament causes a first property change in the filament.
A second, more detectable property change is induced by either twisting the filament or adding a breaking agent, such as a restriction enzyme. These actions cause supercoiling, bending, or breaking of the filament, events that are less likely to be caused by non-specific interactions. The subsequent property change is translated into a detectable signal that facilitates analyte detection, with the method being sensitive enough to detect very low concentrations, even down to a single molecule.
The problem addressed by the invention is the limitation of known analyte detection systems, such as immunoassays or cantilever-based sensors, which suffer from low sensitivity to small analyte concentrations, high background interference, and issues with non-specific binding. The invention provides detection units and methods capable of detecting target analytes at very low concentrations while reducing non-specific binding and background signal, overcoming the constraints of prior approaches.
Claims Coverage
The patent covers five independent claims, each focusing on methods for detecting target analytes using nucleic acid-based filaments and mechanical or chemical property changes.
Method for detecting target analytes using nucleic acid filaments with induced torsional stress
The method comprises: - Exposing a sample containing a target analyte to at least one filament with at least two nucleic acid strands, where at least one strand has an active segment. - Binding of the target analyte to the filament results in either (a) a discontinuous strand becoming continuous, allowing the active segment to accumulate torsional stress, or (b) a continuous strand becoming discontinuous, making the segment unable to accumulate torsional stress. - The filament is attached by at least two connections to each of a first and second surface before further manipulation. - The filament is then exposed to a twisting agent or rotational force, generating a detectable change in the filament's property. - Detection of the property change is performed, with the configuration such that when the target analyte binds, the filament’s tension upon twisting exceeds a linear force separating the surfaces, making them contact and forming an electrical circuit.
Detection using a nanorod and conductive electrode configuration
- The first surface is a nanorod; the second surface is a flat surface with conductive electrodes separated by non-conductive material. - The nanorod is oriented substantially parallel to the surface and perpendicular to the electrodes using a magnetic force. - The rest of the features are as outlined for nucleic acid filaments binding analyte, property changes, exposure to twisting agent or rotational force, and detection of property changes.
Detection based on a conductive or semi-conductive particle and change in electrical property
- The first surface is a conductive or semi-conductive particle; the second surface has electrodes separated by a non-conductive gap. - The two surfaces are separated by a linear force. - When the target analyte binds the filament, tension generated by twisting draws the surfaces together, decreasing the distance and producing a detectable electrical property change in the gap. - All other features correspond to the general method of nucleic acid filament property change after analyte binding.
Filament with discontinuous nucleic acid strand converted to continuous strand by analyte binding
- The at least one filament includes at least one continuous nucleic acid strand and at least one discontinuous nucleic acid strand. - The two ends of the discontinuous strand are capable of binding to different portions of the target analyte. - Binding of the analyte to both ends of the discontinuous strand converts it into a continuous strand, making the active segment capable of accumulating torsional stress. - The rest of the detection method aligns with the described steps of property change, twisting agent exposure, and signal detection.
Detection strategy using breaking agent to cleave double-stranded nucleic acid after analyte binding
- The filament includes at least two continuous single stranded nucleic acids capable of accumulating torsional stress. - Binding of the target analyte to one of the continuous single stranded nucleic acids forms a continuous double stranded nucleic acid. - Exposure of the continuous double stranded nucleic acid to a breaking agent cleaves it, converting it to a discontinuous nucleic acid strand, which renders the active segment incapable of accumulating torsional stress. - The subsequent change in property is detected as a signal.
The inventive features encompass specific physical and chemical changes in nucleic acid filament structures upon target analyte binding, with detection accomplished through mechanically or chemically induced torsional stress, supercoiling, or strand cleavage. The inventions are defined by the configuration of filaments, surfaces, agents or forces applied, and the resultant measurable changes used for detection.
Stated Advantages
The invention allows detection of target analytes at very low concentrations, requiring only a few target molecules or even a single molecule to generate a detectable signal.
It reduces signal interference and background noise caused by non-specific binding and background molecules in the sample.
The method eliminates the need for time-consuming sample purification or amplification steps, as it can detect low concentrations directly.
Supercoiling or breaking-based detection is more easily detected and less likely to be caused by non-specific interactions compared to surface-based binding.
The detection system enables proportional measurement of analyte concentration, allowing quantitative assay capability.
Documented Applications
Detection of natural, synthetic, modified or unmodified nucleic acids or proteins in a sample for general diagnostic purposes.
Use in diagnostic, research, and screening applications involving target analytes such as nucleic acids, proteins, peptides, polypeptides, and others.
Electrical detection of single elongated conductive and semi-conductive nanoparticles using changes in electrical resistance between electrodes.
Monitoring of target analyte binding events via video-microscopy or electrical measurements in various biological and chemical samples.
Detection of specific biomolecules in bodily fluids or environmental samples without requiring extensive sample purification.
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