Aspects of the present disclosure include magnetic sensor devices having a mixed oxide passivation layer. Magnetic sensor devices according to certain embodiments include a magnetic sensor element and a passivation layer having two or more of zirconium oxide, aluminum oxide and tantalum oxide. Also provided are magnetic sensor devices having an encapsulating passivation layer. Magnetic sensor devices according to certain embodiments include a substrate, a magnetic sensor element and a passivation layer that encapsulates the magnetic sensor element. Methods for making a magnetic sensor with a passivation layer are described. Methods and systems for detecting one or more analytes in a sample are also described. Aspects further include kits having one or more of the subject magnetic sensor devices and a magnetic label.

Tunnel magneto-resistive (TMR) sensors employing TMR devices with different magnetic field sensitivities for increased detection sensitivity are disclosed. For example, a TMR sensor may be used as a biosensor to detect the presence of biological materials. In aspects disclosed herein, free layers of at least two TMR devices in a TMR sensor are fabricated to exhibit different magnetic properties from each other (e.g., MR ratio, magnetic anisotropy, coercivity) so that each TMR device will exhibit a different change in resistance to a given magnetic stray field for increased magnetic field detection sensitivity. For example, the TMR devices may be fabricated to exhibit different magnetic properties such that one TMR device exhibits a greater change in resistance in the presence of a smaller magnetic stray field, and another TMR device exhibits a greater change in resistance in the presence of a larger magnetic stray field.

Methods, systems and programing for substance detection with a magnetic sensor are presented. In one example, a magnetic sensor having one or more layers is formed on a base for sensing a magnetic field created by magnetic particles present in proximity to the magnetic sensor. A first end of each of a first set of strands is immobilized with respect to the magnetic sensor. A magnetic particle is attached to a second end of each of the first set of strands so that when a material containing a substance is in contact with the base, the substance causes at least some of the first set of strands to break resulting in that the magnetic particle attached to the second end of each of the at least some of the first set of strands is no longer in proximity to the magnetic sensor.

Systems, devices, and methods for localizing magnets are useful for biological tissue analysis and other applications. Tissue analysis systems for use with a tissue analysis device may include a storage medium storing computer readable instructions that cause the execution of magnet localization methods. The system may include the tissue analysis device, which includes a magnet and a magnetometer array disposed adjacent to the magnet. When executed by a processor, the instructions cause operations, including recording a magnetic field of the magnet with the magnetometer array, simulating a simulated magnetic field at each magnetometer of the magnetometer array, and estimating positional information of the magnet based upon iterating simulated positional information of the simulated magnet.

A nano- or microparticle comprising a matrix consisting of or comprising at least one polyvinyl alcohol (PVA) and dispersed therein, ferrite, and a method for producing the same. Further, the use of these nano- or micro-particles for the preparation and the implementation of devices that can be detected by giant magnetoresistance sensors (GMR sensors) as biological diagnostic tools.

A system for measuring analyte concentrations has porous-walled nanocontainers containing multiple magnetic nanoparticles, the magnetic nanoparticles coated with a selective binder that is analyte-responsive and binds a the analyte, an indicator substance releasable from the selective binder by the analyte, or an indicator substance cleavable by the analyte, apparatus for exposing the nanocontainers to a fluid potentially containing the analyte, and magnetic spectroscopy of Brownian motion sensing apparatus for detecting agglutination of the nanoparticles or binding of analyte to the nanoparticles. The system is used in a method comprising coating magnetic nanoparticles with a selective binder, encapsulating the magnetic nanoparticles in porous nanocontainers, exposing the nanocontainers to a fluid potentially containing analyte, using magnetic spectroscopy of Brownian motion sensing apparatus to detect agglutination or binding of the nanoparticles, and translating Brownian motion spectra to analyte concentrations.

Aspects of the subject technology relate to systems, methods, and computer-readable media for corrosion analysis using magnetic flux leakage measurements. The present technology can magnetic flux leakage data obtained by a magnetic flux leakage tool placed in a pipe within a wellbore and convert the magnetic flux leakage data into image data. Further, the present technology can provide the image data to a machine learning model. The machine learning model is configured to identify one or more physical parameters associated with corrosion present on the pipe.

Methods and apparatuses for sensing biological functions are disclosed. Sensors can be implanted in an organ, such as the brain, and a magnetic field gradient applied to the biological tissue. The field causes the sensors to have different resonant frequencies allowing their spatial localization. The sensors can harvest power from the external coils to be able to retransmit data.

The inventive concepts presented herein relate to methods of identifying molecules identification of molecules using apparatuses including: electromagnetic write-head(s); magneto-resistive read sensor(s), and processor(s). An exemplary method includes scanning one or more of a plurality of biosample tracks of a biosample substrate using an electromagnetic write-head to magnetically excite one or more molecules of interest using an alternating magnetic field. The one or more molecules of interest are disposed on one or more of the biosample tracks. A resonant response of the one or more molecules of interest is measured using a magneto-resistive sensor. The resonant response is compared to a table of known resonant responses to identify the one or more molecules of interest.

An apparatus for magnetic flux density based DNA sequencing. The apparatus comprising a device for generating a static magnetic field; a nanopore device; a gel medium; and a magnetometer for measuring a change in magnetic flux density of the static magnetic field as a chain of nucleotides travels through the gel medium.