Method and device for analysing a sample, implementing a resonant support

Patent metadata

Field	Value
Publication number	US-12072282-B2
Application number	US-202017616908-A
Country	US
Kind code	B2
Filing date	Jun 4, 2020
Priority date	Jun 7, 2019
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

A method for analysing a sample uses a resonant support having a surface on which a plurality of separated photonic crystals extends. At least two crystals are configured to capture the same analyte. A resonance wavelength associated with each crystal varies with an amount of analyte in contact with the crystal. The wavelengths define a resonance spectral band between 200-1500 nm. The transmission/reflection of the light is maximum at an associated resonance wavelength. The method includes: illuminating the support in the resonance spectral band, the intensity of the lamination being variable in band; acquiring a measurement image using an image sensor, the image having different regions-of-interest each optically coupled to a photonic crystal; using a reference image representative of an image acquired by the image sensor, when the support is illuminated in the resonance spectral band in a reference configuration; and comparing the measurement image with the reference image.

First claim

The invention claimed is:

1. A method for detecting an analyte within a sample, the sample lying on a resonant holder, the resonant holder comprising a surface on which lie a plurality of photonic crystals, which are separate from one another, such that the sample lies between a light source and the photonic crystals, the photonic crystals being such that:
at least two of the photonic crystals are configured to make contact with the same analyte,
one resonant wavelength is associated with each photonic crystal, the resonant wavelength varying as a function of an amount of analyte in contact with each photonic crystal, the resonant wavelengths of the photonic crystals defining a resonance spectral band lying between 200 nm and 1500 nm; and
transmission or reflection of light by each photonic crystal is maximum at the associated resonant wavelength;
the method comprising:
a) illuminating the resonant holder with the light source in an illumination spectral band that at least partially covers the resonance spectral band, such that a plurality of photonic crystals addressing the analyte are simultaneously illuminated and an illumination intensity is variable, in the resonance spectral band, according to a spectral illumination function;
b) acquiring, with an image sensor, a measurement image of the resonant holder, the measurement image comprising different regions of interest, each region of interest being optically coupled to one photonic crystal such that each region of interest represents an intensity transmitted or reflected by each photonic crystal while the resonant holder is illuminated;
c) using a reference image, the reference image being representative of an image acquired by the image sensor, when the resonant holder is illuminated in the illumination spectral band in a reference configuration, in the absence of analyte;
d) comparing the measurement image, acquired in b), with the reference image; and
e) based on the comparison, determining whether the analyte is present in the sample,
wherein
each photonic crystal comprises:
first holes formed in a thin layer and having a first dimension, the first dimension being a radius or a diagonal, the first holes defining a first periodic pattern; and
second holes formed in the thin layer and having a second dimension, the second dimension being strictly smaller than the first dimension, the second holes defining a second periodic pattern;

the second pattern and the first pattern are offset with respect to each other, parallel to the surface of the resonant holder by a spatial offset, the spatial offset being variable between at least two different photonic crystals; and
the resonant wavelength associated with each photonic crystal depends on the first dimension, on the second dimension, and on the spatial offset.

2. The method of claim 1 , wherein a plurality of photonic crystals are aligned in a row parallel to a longitudinal axis, such that the resonant wavelength respectively associated with a photonic crystal gradually increases, or decreases, along the longitudinal axis.

3. The method of claim 2 , wherein:
the resonant holder comprises rows of photonic crystals parallel to one another to form columns, parallel to a lateral axis; and
photonic crystals of a given column have a same resonant wavelength.

4. The method of claim 1 , wherein:
the photonic crystals lie in a holder plane;
the light source produces an illuminating light wave; and
the illuminating light wave propagates to the resonant holder parallel to a propagation axis that is perpendicular or substantially perpendicular to the holder plane.

5. The method of claim 1 , comprising, prior to a):
illuminating the resonant holder with the light source, in the illumination spectral band; and
acquiring an image of the resonant holder with the image sensor as the reference image, the amount of analyte in contact with the resonant holder being considered to be zero.

6. The method of claim 1 , comprising obtaining the reference image by:
illuminating, in the illumination spectral band, a reference holder considered to be representative of the resonant holder illuminated in a), the amount of analyte in contact with the reference holder being considered to be zero; and
forming an image of the reference holder.

7. The method of claim 6 , wherein:
the resonant holder comprises reference photonic crystals that are considered not to make contact with the analyte; and
the reference image is an image of the reference photonic crystals illuminated in the illumination spectral band.

8. The method of claim 7 , wherein the reference image and the measurement image form two parts of the same image acquired by the image sensor.

9. The method of claim 1 , wherein, for each photonic crystal addressing the analyte, the resonant wavelength depends on a refractive index of the sample, at an interface between the sample and the photonic crystal, the refractive index varying as a function of the amount of analyte making contact with the photonic crystal.

10. The method of claim 1 , wherein e) comprises:
on a basis of the measurement image, determining a measurement profile of the intensity of the regions of interest associated with the analyte; and
on a basis of the reference image, determining a reference profile of the intensity, in an absence of analyte or in a presence of a known amount of analyte in the sample, of the regions of interest associated with the analyte,
wherein whether the analyte is present is determined depending on a variation in the measurement profile with respect to the reference profile.

11. The method of claim 10 , wherein e) comprises estimating an amount of analyte in the sample, depending on the comparison between the measurement image and the reference image and depending on a variation in the measurement profile of the intensity of the regions of interest associated with the analyte with respect to the reference profile.

12. The method of claim 1 , wherein e) comprises:
in the measurement image, determining a measurement position of a region of interest exhibiting a maximum intensity value among the regions of interest associated with the analyte; and
in the reference image, determining the reference position of a region of interest exhibiting a maximum intensity value among the regions of interest associated with the analyte,
wherein whether the analyte is present is determined depending on a variation in the measurement position with respect to the reference position.

13. The method of claim 12 , wherein e) comprises estimating an amount of analyte in the sample, depending on the comparison between the measurement image and the reference image and depending on a variation in the measurement position with respect to the reference position.

14. The method of claim 1 , wherein e) comprises estimating an amount of analyte in the sample, depending on the comparison between the measurement image and the reference image.

15. The method of claim 1 , wherein:
the photonic crystals addressing the analyte are aligned along a longitudinal axis; and
the resonant wavelengths respectively associated with two adjacent photonic crystals are offset by a discretization pitch comprised between 1 nm and 10 nm.

16. The method of claim 1 , wherein the photonic crystals addressing the analyte are covered with a functionalization layer configured to selectively capture the analyte on the photonic crystals.

17. The method of claim 16 , wherein the resonant holder comprises:
photonic crystals of rank l configured to capture a first analyt

Assignees

• Centre Nat Rech Scient
• Cpe Lyon Formation Continue Et Rech
• Lyon Ecole Centrale
• Inst Nat Sciences Appliquees Lyon
• Univ Claude Bernard Lyon
• Avalun
• Commissariat Energie Atomique
• Univesite Claude Bernard Lyon 1

Inventors

• Dupoy Mathieu
• Benyattou Taha
• Berguiga Lotfi
• Fedeli Jean-Marc
• Fournier Maryse
• Gaignebet Nicolas
• Jamois Cecile
• Pouteau Patrick

Classifications

• G01N2021/5957

  using an image detector type detector, e.g. CCD · CPC title

• G01N2021/438

  with investigation of wavelength · CPC title

• G01N2021/3137

  with selection of wavelengths after the sample · CPC title

• G01N2021/4126

  Index of thin films · CPC title

• G01N21/359

  using near infrared light · CPC title