# US 2021/0333296 A1 · Opto-magnetophoretic method for the detection of biological and chemical substance

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2021/0333296 A1
- Document ID: US20210333296A1
- Status: Published application
- Kind: A1
- Application number: 16/613,401
- Filed: 2018-05-30
- Published: 2021-10-28
- Earliest claimed: 2018-05-30
- Assignees: Pragmatic Diagnostics, S.L.; Sepmag Systems, S.L.
- Applicants: Pragmatic Diagnostics, S.L.; Sepmag Systems, S.L.
- Inventors: Maria BENELMEKKI ERRETBY; Sergi GASSÓ PONS; Lluís Miquel MARTÍNEZ GARCÍA
- Web page: https://patentgrep.com/patent/US20210333296A1

## CPC

- G01N 35/0098: {involving analyte bound to insoluble magnetic carrier, e.g. using magnetic separation (magnetic particles used in immunoassays G01N33/54326; magnetic separation in general B03C)}
- B03C 1/01: by addition of magnetic adjuvants
- B03C 1/0332: {using permanent magnets}
- B03C 1/288: {disposed at the outer circumference of a recipient}
- B03C 1/30: Combinations with other devices, not otherwise provided for
- B03C 1/32: acting on the medium containing the substance being separated, e.g. magneto-gravimetric-, magnetohydrostatic-, or magnetohydrodynamic separation
- G01N 15/02: Investigating particle size or size distribution (by measuring osmotic pressure G01N7/10; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10)
- G01N 21/59: Transmissivity (G01N21/25 takes precedence)
- G01N 21/82: producing a precipitate or turbidity
- B01L 3/502761: {specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads or physically stretching molecules}
- B03C 2201/18: Magnetic separation whereby the particles are suspended in a liquid
- B03C 2201/22: characterised by the magnetic field, e.g. its shape or generation
- B03C 2201/26: for use in medical or biological applications
- B82Y 5/00: Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
- B82Y 25/00: Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
- B82Y 35/00: Methods or apparatus for measurement or analysis of nanostructures
- G01N 15/075: by optical means
- G01N 33/54326: {Magnetic particles}
- G01N 2015/0092: {Monitoring flocculation or agglomeration}
- G01N 2015/0277: {Average size only}
- G01N 2021/825: {Agglutination}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B03C: MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS (separating isotopes B01D59/00; combinations of magnetic or electrostatic separation with separation of solids by other means B03B, B07B)
- B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

Method for detecting the presence or absence of a biological or chemical substance in a particular sample mixed with a suspension with functionalized magnetic particles, comprising: providing a light source and detector, providing a constant magnetic force perpendicular to the light's propagation direction by applying a constant magnetic field gradient, and with an absolute value which is higher than 0.1 T and measuring the change of the magnetic particle's suspension transparency versus time and comparing it with the time-variation in absence of the targeted biological or chemical substance. The method of the invention allows monitoring the transparency irrespective of the emitted wavelength and particle's optical properties.

## Claims

### Claim 1

A method for detecting the presence or absence of a biological or chemical substance in a particular sample mixed with a suspension with functionalized magnetic particles, the particles having a diameter between 10 and 1000 nm and a saturation magnetization such that their magnetic separation time is different in the absence or presence of the biological or chemical substance, by monitoring the optical properties of the suspension, the method comprising the steps of:
providing a light source and detector;
providing a constant magnetic force perpendicular to the light's propagation direction by applying a constant magnetic field gradient, and with an absolute value of the magnetic field which is higher than 0.1 T;
measuring the change of the magnetic particle's suspension transparency versus time and
comparing the variation along time of the magnetic particle's suspension transparency in the presence and in the absence of the biological or chemical substance of interest.

### Claim 2 (depends on 1)

The method for detecting the presence of a biological or chemical substance in a suspension with functionalized magnetic particles, according to claim 1, wherein the magnetic force is provided by a magnetic force generator comprising permanent magnets.

### Claim 3 (depends on 2)

The method according to claim 2, wherein the magnetic force generator is formed by at least four permanent magnets following the Halbach progression for a quadrupole in a cylindrical support.

### Claim 4 (depends on 2)

The method according claim 2, wherein the magnetic force generator is formed by two sets of magnets with opposite polarities.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the detector is a spectrophotometer.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the magnetic moment of the particles is less than 10−16 A/m2.

### Claim 7 (depends on 1)

The method according to claim 1, wherein the light source is a UV-visible source.

### Claim 8 (depends on 2)

The method according to claim 2, wherein the detector is a spectrophotometer.

### Claim 9 (depends on 3)

The method according to claim 3, wherein the detector is a spectrophotometer.

### Claim 10 (depends on 4)

The method according to claim 4, wherein the detector is a spectrophotometer.

### Claim 11 (depends on 2)

The method according to claim 2, wherein the magnetic moment of the particles is less than 10−16 A/m2.

### Claim 12 (depends on 3)

The method according to claim 3, wherein the magnetic moment of the particles is less than 10−16 A/m2.

### Claim 13 (depends on 4)

The method according to claim 4, wherein the magnetic moment of the particles is less than 10−16 A/m2.

### Claim 14 (depends on 5)

The method according to claim 5, wherein the magnetic moment of the particles is less than 10−16 A/m2.

### Claim 15 (depends on 2)

The method according to claim 2, wherein the light source is a UV-visible source.

### Claim 16 (depends on 3)

The method according to claim 3, wherein the light source is a UV-visible source.

### Claim 17 (depends on 4)

The method according to claim 4, wherein the light source is a UV-visible source.

### Claim 18 (depends on 5)

The method according to claim 5, wherein the light source is a UV-visible source.

### Claim 19 (depends on 6)

The method according to claim 6, wherein the light source is a UV-visible source.

### Claim 20 (depends on 14)

The method according to claim 14, wherein the light source is a UV-visible source.