Abstract:
A magnetic tunnel junction having a first electrode separated from a second electrode by a tunneling barrier is provided. The tunneling barrier is a ferromagnetic insulator that provides a spin dependent barrier energy for tunneling. The first electrode includes a ferromagnetic, electrically conductive layer. Electrons emitted from the first electrode toward the tunneling barrier are partially or completely spin-polarized according to the magnetization of the ferromagnetic electrode layer. The electrical resistance of the tunnel junction depends on the relative orientation of the electrode layer magnetization and the tunneling barrier magnetization. Such tunnel junctions are widely applicable to spintronic devices, such as spin valves, magnetic tunnel junctions, spin switches, spin valve transistors, spin filters, and to spintronic applications such as magnetic recording, magnetic random access memory, ultrasensitive magnetic field sensing (including magnetic biosensing), spin injection and spin detection.
Abstract:
Dumbbell-shaped or flower-shaped nanoparticles and a process of forming the same, wherein the process comprises forming a mixture of a nanoparticle with a precursor in a first solvent, wherein the nanoparticle comprises a hydrophobic outer coating; heating the mixture; cooling the mixture to room temperature; modifying the hydrophobic outer coating into a hydrophilic outer coating; precipitating a solid product from the mixture, and dispersing the product in a second solvent. The nanoparticles comprise any of a semiconducting, magnetic, and noble metallic material, wherein the nanoparticles comprise a first portion comprising any of PbSe, PbS, CdSe, CdS, ZnS, Au, Ag, Pd, and Pt, and wherein the precursor comprises any of a cationic, neutral or particulate Au, Ag, Pd, Pt, or transition metal (Fe, Co, Ni) precursors of Fe(CO)5, Co(CO)8, Ni(CO)4 or their analogues. The first and second solvents comprise any of alkanes, arenes, ethers, nitrites, ketones, and chlorinated hydrocarbons.
Abstract:
The present invention provides a magnetic sifter that is small in scale, enables three-dimensional flow in a direction normal to the substrate, allows relatively higher capture rates and higher flow rates, and provides a relatively easy method of releasing captured biomolecules. The magnetic sifter includes at least one substrate. Each substrate contains a plurality of slits, each of which extends through the substrate. The sifter also includes a plurality of magnets attached to the bottom surface of the substrate. These magnets are located proximal to the openings of the slits. An electromagnetic source controls the magnitude and direction of magnetic field gradient generated by the magnets. Either one device may be used, or multiple devices may be used in series. In addition, the magnetic sifter may be used in connection with a detection chamber.
Abstract:
The present invention provides microfluidic devices constructed from four layers. The layers include a rigid substrate layer, a patterned rigid layer having thickness t, a patterned elastomeric layer having thickness greater than t, and a rigid support layer. Microfluidic structures in the devices are defined by the alignment of openings in the patterned rigid layer and the patterned elastomeric layer. The rigid support layer, rigid substrate layer, and patterned rigid layer may be made of any rigid material, including but not limited to plastic or silicon-containing materials, such as glass, quartz, or SiO2-coated materials. Similarly, the patterned elastomeric layer may be made of any elastomeric material, including but not limited to polydimethylsiloxanes, polymethylmethacrylates, perfluoropolyethers, or combinations thereof. Microfluidic devices according to the present invention may include sensors or sensor arrays. The microfluidic devices are fabricated using the provided error-tolerant alignment, biocompatible process.
Abstract:
A method of determining the length of a polynucleotide target is provided. With this method, a target is first hybridized to an array of first probes having different, determined lengths, resulting in the formation of duplexes between the polynucleotide target and the first probes. These duplexes have a single stranded section of target if the target is longer than the first probe it is in a duplex with. Next, a second probe having a determined length is hybridized to these duplexes. If the length of the target is greater than the length of the first probe it is displaced during this hybridization step by the process of branch migration. In contrast, if the length of the target is less than or equal to the length of the first probe, it is not displaced. Thus, the length of the polynucleotide target can be determined.
Abstract:
The signaling used in saturation magnetic recording is described as pulse width modulation (“PWM”). A continuous range of magnet lengths are defined between a minimum length (the smallest magnet length that can be written) and a maximum length (the longest magnet that can be read without losing clock synchronization). The recorded magnets are then partitioned into cosets according to the position of the last transition in the magnet. A finite state convolutional encoder can be used to constrain the sequence of magnet cosets. Instead of using these variable length symbols, however, the code is expressed in terms of a synchronous PAM channel, in which two consecutive transitions define a magnet. Using this expression, the code constraint on transition position is an equivalent constraint on magnet length. An appropriate encoder is created to encode the constrained code. A Viterbi detector, which reflects the code constraints, has states which are the product of the channel states of a conventional PRML detector and the encoder states. Because of the constraints, only a small subset of all branches are permitted at each resulting trellis update. A conventional sliding block decoder can be used to decode the data. In this way, a complete coded recording system can be constructed using standard building blocks of existing PRML channels, namely, a finite state encoder, a Viterbi detector and a sliding block decoder.
Abstract:
Methods for analyte detection with magnetic sensors are provided. Aspects of the methods include producing a magnetic sensor device having a magnetically labeled analyte from a sample, such as a serum sample, bound to a surface of a magnetic sensor thereof; and obtaining a signal, e.g., a real-time signal, from the magnetic sensor to determine whether the analyte is present in the sample. Also provided are devices, systems and kits that find use in practicing the methods of the invention. The methods, devices, systems and kits of the invention find use in a variety of different applications, including detection of biomarkers, such as disease markers.
Abstract:
Embodiments of the present disclosure provide for nanoprobes, methods of imaging, methods of imaging a target, methods of making nanoprobes, and the like.
Abstract:
A Raman-active nanoparticle is provided that includes a dish-shape plasmonically active metal base, and a plasmonically active metal pillar disposed on the plasmonically active metal base, where the plasmonically active metal pillar is disposed within the dish-shape plasmonically active metal base and normal to a bottom of the dish-shape plasmonically active metal base, where a circular gap is disposed between the dish-shape plasmonically active metal pillar and inner walls of the dish-shape plasmonically active metal base. In one embodiment a Raman-active nanoparticle is provided that includes a dish-shape base having a dielectric material, an electrically conductive layer disposed on the inner surface of the dish-shape base, and an electrically conductive pillar disposed on the conductive layer, and within the dish-shape and perpendicular to a bottom of the dish-shape base, where a circular gap is disposed between the conductive pillar and inner walls of the dish-shape base.
Abstract:
Methods for quantitatively determining a binding kinetic parameter of a molecular binding interaction are provided. Aspects of embodiments of the methods include: producing a magnetic sensor device including a magnetic sensor in contact with an assay mixture including a magnetically labeled molecule to produce a detectable molecular binding interaction; obtaining a real-time signal from the magnetic sensor; and quantitatively determining a binding kinetics parameter of the molecular binding interaction from the real-time signal. Also provided are systems and kits configured for use in the methods.