A compact optical device for detecting and / or measuring particle or biomolecular interactions and a method for manufacturing such

Abstract

The present disclosure relates to an optical device (100) comprising a transparent sensor substrate (101) having a sensing portion (102). Further, the optical device (100) comprises an sample supply unit (104) attached to the transparent sensor substrate, the sample supply unit (104) being arranged to introduce an sample onto the sensing portion (102). Further, the optical sensor device (100) comprises a light-emitting and detecting unit (105) affixed to the sensor substrate (101), and at least one optical metasurface (106) interfaced with at least one light source (106a) of said at least one light-emitting and detecting unit (105). Furthermore, the optical device (100) is configured to emit a beam (110a) for generation of a guided mode at the sensing portion (102). Further, the optical device (100) is configured to receive a reflected beam (110b) and monitor properties of said reflected beam (110b), said properties being indicative of changes in refractive index.

Description

[0001] A compact optical device for detecting and / or measuring particle or biomolecular interactions and a method for manufacturing such

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to an optical device and a method for manufacturing of such an optical device.

[0004] BACKGROUND

[0005] Optical devices may be used for detecting and / or measure particle or biomolecular interactions in real-time. Such optical devices may be operable to generate a guided optical mode localized at an interface when exposed to incident light. In such an optical device setup, a target analyte, which may be a specific protein, nucleic acid, or other (small) particle, interacts with a prepared surface which leads to changes in the refractive index, or other optical properties, at the interface where the guided mode is localized. As the interaction occurs, the properties of the reflected beam changes, and this change can be monitored in real-time.

[0006] By monitoring, one can quantitatively analyse at least one of binding kinetics, affinity, and concentration of the target analyte. Optical devices find applications in various fields, including medical diagnostics, environmental monitoring, and drug development, due to their high sensitivity, specificity, and real-time monitoring capabilities.

[0007] Optical devices have been commercialized since many years. However, conventional optical devices are bulky, fragile and expensive. Consequently, such optical devices are only really found in large pharma industry and large research labs.

[0008] Accordingly, there is a need for improved optical devices for detecting and / or measuring biomolecular interactions in real-time which are at least more compact, robust and less expensive. SUMMARY

[0009] It is therefore an object of the present disclosure to alleviate at least some of the mentioned drawbacks to provide an optical device and a method for manufacturing such.

[0010] The present disclosure is at least partly based on the insight that the optical device herein is improved compared to conventional optical devices as it is more compact, cost-efficient and robust than conventional optical devices.

[0011] The present disclosure relates to an optical device. The device may also be referred to as an optical sensor device or an optical biosensor device. The optical device comprises a transparent sensor substrate having a sensing portion, the sensing portion being affixed to the sensor substrate. Further, comprising a sample supply unit attached to the sensor substrate, the sample supply unit being arranged to introduce at least one sample onto the sensing portion. Further, the device comprises a light-emitting and detecting unit affixed to the sensor substrate and at least one optical metasurface interfaced with a light source of said at least one light-emitting and detecting unit. The term "metasurface" may be interchanged with metasurface structure. Moreover, the optical device is configured to emit, from the light source, a beam, through said transparent sensor substrate to the sensing portion, wherein said the at least one optical metasurface is dimensioned to produce a specific emission pattern from said beam, preferably an angular emission pattern covering a set of angles required for generation of an guided mode at the sensing portion, this guided mode being sensitive to the optical properties of a sample at the surface of, or in the vicinity of, the sensing portion. Le. at an interface of the sensing portion e.g. directly at the sensing portion or at an area associated with the sensing portion.

[0012] Further, the optical device is configured to receive, at the light-emitting and detecting unit, a reflected beam, the reflected beam being reflected via said sensing portion. Further, the optical device is configured to monitor, by the light-emitting and detecting unit, properties of said reflected beam, said properties being indicative of changes in optical properties of a substance at the surface of, or in the vicinity of the sensing portion. The optical property may be the refractive index of sample at the surface of, or in the vicinity of, the sensing portion Advantageously, the dimensions of the optical metasurface enables the light source to produce a specific emission pattern / an angular emission pattern, combined with that the optical metasurface is interfaced with the light source, allows the optical device herein to be less bulky, more robust and less expensive compared to conventional optical devices. In other words, the device is cheaper to produce, is more compact (likely factor of 10-100 reduction in volume and weight).

[0013] The optical device may be a portable optical device. Accordingly, the optical device may be a miniature optical device. The optical device may have a graphical user interface (GUI), or be arranged to, by wired or wireless communication, connect to a graphical user interface of a user equipment device (e.g. a mobile phone, laptop, tablet or the like). The optical device may, based on the monitoring, provide an output at said GUI, the output being indicative of a presence, binding kinetics, affinity, or concentration of at least one specific molecule, or other type of particle, which we define as the analyte, in the at least one sample.

[0014] The light-emitting and detecting device may comprise control circuitry configured to monitor properties of said reflected beam, said properties being indicative of changes in optical properties of the sample at the surface of, or in the vicinity of, the sensing portion. The control circuitry may monitor the properties in several ways, e.g. by determining changes in intensity, phase or polarization of the reflected beam. Le. property may be intensity, phase, polarization or any other suitable metric. Accordingly, the control circuitry may be configured to further determine, based on said monitoring, at least one of a presence, binding kinetics, affinity, and concentration of a specific analyte in the sample. The sample may be a fluid, preferably a liquid. The monitoring may be performed in real-time.

[0015] Generally, the metasurface / metasurface structure may be dimensioned to produce an angular emission pattern from a beam received from the light source. The metasurface may be dimensioned in a variety of ways to produce said angular emission pattern, as appreciated by a skilled person in the art. The metasurface may be dimensioned to produce a pre-determined angular emission pattern based on a beam having a pre-determined characteristic (such as wavelength, intensity divergence or frequency). Preferably, the metasurface is a metagrating, more preferably an offset-axicon based metagrating. The metagrating may have constant or substantially constant trench width, i.e. the width of the trenches or gaps between the nanoscale or subwavelength structures that make up the grating. The metagrating can be transformed into an axicon by curving the ridges into concentric circles.

[0016] The sensing portion may comprise or consist of at least one film layer deposited on the transparent substrate, preferably, the film layer may be composed of a metal, or other suitable material. The transparent substrate may be any suitable transparent substrate such as glass or the like. The film layer may have a thickness / structural characteristic adapted to support a guided mode.

[0017] Accordingly, the sensing portion maintains compactness of the device. The film may facilitate a guided mode, e.g. a surface plasmon mode or waveguided mode, at the sensing portion. Accordingly, allowing for sensing of, for example the refractive index changes of a sample at the surface of the sensing portion. Preferably, the guided mode is a surface plasmon mode or a waveguided mode that produces an electromagnetic evanescent field at the interface between the film and the sample.

[0018] The sample supply unit may be a microfluidic unit having at least one channel in fluidic contact with said sensing portion and at least one inlet for introducing said analyte to said channel.

[0019] Advantageously, the microfluidic unit may comprise microchannels which allows the device to use sample volumes. The microfluidic unit may comprise at least one valve and / or at least one pump for controlling flow of the one or more analytes within the channel. The pump may be any suitable type of pump such as a hydraulic or electric pump.

[0020] Further, the sample supply unit may have at least one inlet for receiving a sample which is to flow into at least one channel. Subsequently, analytes present within the sample will attach to the film. Hence, the sample supply unit may in some aspects herein have a plurality of inlets, each associated with a corresponding channel of a plurality of channels. Moreover, the device may comprise a plurality of light sources, each one being associated with at least one corresponding channel. Advantageously, this may allow for a plurality of samples to be measured simultaneously (eg. 2-100 samples) which would cut down lead times in screening and research. The sample supply unit may together with the transparent sensor substrate be releasably attached to the light emitting and detecting device by an adhesive, such as a pressuresensitive adhesive (PSA), optical adhesive, microscope oil or any other suitable adhesive.

[0021] The light-emitting and detecting unit may be affixed to a top surface of said sensor substrate, wherein the sensing portion is affixed to an opposite bottom surface of said sensor substrate, wherein the top surface and the bottom surface are parallel.

[0022] Such a configuration provides a more compact structure that is more convenient for handling by a user. The top and bottom surfaces may be substantially flat, preferably fully flat. The light-emitting and detecting unit, transparent sensor substrate and analyte supply unit may each be formed as a block such that the device is formed by layered blocks, wherein the transparent sensor substrate is sandwiched between the light-emitting and detecting unit and the sample supply unit.

[0023] The light-emitting and detecting unit may comprise, at a (flat) upper surface thereof, a light emitting portion for emitting said beam and a light detecting portion for receiving said reflected beam. The light emitting and detecting portions may be spaced apart. The lightemitting and detecting unit may comprise a light detector for monitoring said properties, the light detector may be at said light detecting portion. The light detector may comprise of arrays of light scatterers, an optoelectronic light detector or a photoluminescence material. The light source may be at said light emitting portion and may be a vertical-cavity surface-emitting laser. Hence, the light source may comprise a structure forming a cavity which has an axial extension perpendicular to the upper surface (and the metasurface) such to extend along a vertical axis. An advantage of having a vertical-cavity surface-emitting laser is that they are compact, efficient, and robust.

[0024] The at least one optical metasurface may be interfaced with the light-emitting and detecting unit by being at least one of: being monolithically etched into a substrate of the light source of the light-emitting and detecting unit or etched into a thin film deposited on the substrate of the light source of the light-emitting and detecting unit. The substrate of the light source may be varying depending on the type of light source. Nonetheless, the substrate of the lightsource may be a part of the light-source through which the beam is transferred and may be formed by a semiconductor material such as gallium nitride (GaN) or gallium arsenide (GaAs) or any other suitable material.

[0025] Accordingly, the optical metasurface may be interfaced with the light-emitting and detecting unit in several manners according to the present disclosure.

[0026] Generally, the optical device may be formed as a single laminated / layered / one-piece structure which may be formed as a rectangular / six-sided block.

[0027] The metasurface may be composed of gallium arsenide, gallium nitride, silicon, titanium dioxide or any other material with suitable optical properties.

[0028] The present disclosure further relates to a method for manufacturing the optical device of any aspect herein. The method comprising the steps of: providing said transparent sensor substrate having a sensing portion; providing said light-emitting and detecting unit; forming / patterning at least one optical metasurface on said light-emitting and detecting unit or said transparent sensor substrate, the at least one optical metasurface being dimensioned to produce a (specific) emission pattern from said beam, preferably an angular emission pattern covering a set of angles required for generation of a guided mode at the sensing portion, such as a surface plasmon mode or waveguided mode which alters the intensity, or any other property, of the reflected beam.

[0029] Further, the method comprises the steps of affixing said light-emitting and detecting unit to said sensor substrate and attaching a sample supply unit to said sensor substrate. The transparent sensor substrate, light-emitting and detecting unit and sample supply unit may form a layered / laminated structure such that the optical device is a laminated device formed as one piece.

[0030] Advantageously, the method is convenient, rapid and cost-efficient to perform.

[0031] The present disclosure further provides a method for operating the optical device according to any aspect herein. The method comprising the steps: Emitting, by the light source, a beam, through said transparent sensor substrate to the sensing portion, wherein said the at least one optical metasurface is dimensioned to produce a specific emission pattern from said emitted beam, for example an angular emission pattern covering a set of angles required for generation of an guided mode at the sensing portion, preferably a surface plasmon mode, or a waveguided mode, which alters the intensity, or any other optical property, of the reflected beam.

[0032] Receiving, at the light-emitting and detecting unit, a reflected beam, the reflected beam being reflected via said sensing portion

[0033] Monitoring by the light-emitting and detecting unit properties of said reflected beam, said properties being indicative of changes in refractive index, or other optical property, of a sample, at the surface of, or near the vicinity of, the sensing portion.

[0034] BRIEF DESCRIPTION OF THE DRAWINGS

[0035] These and other features and advantages of the present disclosure will now be further clarified and described in more detail, with reference to the appended drawings;

[0036] Figure 1 illustrates a side-cross-sectional view of an optical device connected to a schematically illustrated control circuitry;

[0037] Figure 2 illustrates an objective view of an sample supply unit;

[0038] Figure 2 illustrates a part of an optical device viewed from a side cross-sectional view; and

[0039] Figure 4 illustrates, in the form of a flowchart, a method for manufacturing an optical device; and

[0040] Figure 5 illustrates, in the form of a flowchart, a method for operating an optical device.

[0041] DETAILED DESCRIPTION

[0042] In the following detailed description, some embodiments of the present disclosure will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. Even though in the following description, numerous specific details are set forth to provide a more thorough understanding of the present disclosure, it will be apparent to one skilled in the art that the present disclosure may be practiced without these specific details. In other instances, well known constructions or functions are not described in detail, so as not to obscure the present disclosure.

[0043] It is also to be understood that the terminology used herein is for purpose of describing particular aspects only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context clearly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may refer to more than one unit in some contexts, and the like. Furthermore, the words "comprising", "including", "containing" do not exclude other elements or steps. It should be emphasized that the term "comprises / comprising" when used in this specification is taken to specify the presence of stated features, integers, steps, or components. It does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof. The term "and / or" is to be interpreted as meaning "both" as well and each as an alternative. More specifically, the wording "one or more" of a set of elements (as in "one or more of A, B and C" or "at least one of A, B and C") is to be interpreted as either a conjunctive or disjunctive logic. Put differently, it may refer either to all elements, one element or combination of two or more elements of a set of elements. For example, the wording "A, B and C" may be interpreted as A or B or C, A and B and C, A and B, B and C, or A and C.

[0044] The term "metasurface" may refer to a surface having subwavelength elements arranged thereon. The subwavelength elements being in the form of e.g. nanostructures, microstructures or the like and are arranged in a specific pattern to achieve a desired optical emission pattern.

[0045] The term "light-emitting and detecting unit" may refer to a single structure which has a light source and a detector arranged thereon. The light source and the detector may both be positioned on a common surface. The term "guided mode" herein may refer to an arising of electromagnetic waves at an interface between the film and the transparent substrate, or within the film, which in turn alter the optical properties of the reflected beam. Preferably, the arising of the electromagnetic waves occur when an emitted beam, with specific properties, from a light source interacts with a dielectric-metal interface. Preferably, the arising of the electromagnetic waves occur when an emitted beam, with specific properties, from a light source interacts with the dielectric-metal interface. The term "guided mode" may be a "surface plasmon mode", i.e. the terms may be interchanged within some aspects herein.

[0046] Figure 1 illustrates an optical device 100 from a side cross-sectional view. The optical device 100 comprising a transparent sensor substrate 101 having a sensing portion 102, the sensing portion 102 being affixed to the transparent sensor substrate 101. Figure 1 further illustrates that the optical device 100 comprises an sample supply unit 104 attached to the transparent sensor substrate, the sample supply unit 104 being arranged to introduce a sample onto the sensing portion 102. As illustrated in Figure 1, the sample supply unit 104 comprises a channel 104a in fluidic communication with the sensing portion 102 which allows analyte compounds within the sample to attach to the film.

[0047] Figure 1 further illustrates that the optical device 100 comprises a light-emitting and detecting unit 105 affixed to the sensor substrate 101. Further, Figure 1 illustrates that the device 100 comprises at least one optical metasurface 106 interfaced with at least one light source 106a of said at least one light-emitting and detecting unit 105. Moreover, Figure 1 illustrates that the optical device 100 is configured to emit, by the light source 106a, a beam 110a, through said transparent sensor substrate 101 to the sensing portion 102, wherein said the at least one optical metasurface 106 is dimensioned to produce a specific emission pattern 108 from said emitted beam 110a, the emission pattern 108 covering a set of angles required for generation of a surface plasmon mode 109 at the sensing portion 102. In some aspects, the surface plasmon model09 at the sensing portion 102 may be another waveguided mode that alters the optical properties of the reflected beam. The angles may be relative a vertical axis xl. Moreover, Figure 1 illustrates that the optical device 100 is configured to receive, at the lightemitting and detecting unit 105, a reflected beam 110b, the reflected beam 110b being reflected via said sensing portion 102. Moreover, the optical device 100 is configured to monitor, by the light-emitting and detecting unit 105 properties of said reflected beam 110b, said properties being indicative of changes in the optical properties of a sample at the surface of, or in the vicinity of, the sensing portion.

[0048] Figure 1 further illustrates that the optical device 100 may comprise control circuitry 120 which may be configured to monitor. Also, the control circuitry 120 may be configured to, based on the monitoring, determine a presence, concentration, affinity of one or more analyte in said sample.

[0049] The control circuitry 120 may be integrated on the optical device 100 e.g. in the form of an integrated circuit (IC). The control circuitry 120 may comprise one or more memory devices 121. The memory device 121 may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device readable and / or computer-executable memory devices that store information, data, and / or instructions. Each memory device 121 may store any suitable instructions, data, simulation models or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and / or other instructions capable of being utilized so to monitor properties of said reflected beam 110b relative to the emitted beam 110a. The control circuitry 120 may be integrated with the light-emitting and detecting device 105. Moreover, the control circuitry 120, may via the interfaces 122 communicate, by wired or wireless communication, to a user equipment device 130 so to output said monitoring or determined characteristics (e.g. presence, absence, concentration and / or affinity of an analyte) derived based on said monitoring.

[0050] The control circuitry 120 may provide a graphical output for being presented / outputted on a GUI of a user equipment 130. Hence, the control circuitry may output graphically, said monitoring or determined characteristics at said GUI.

[0051] Figure 1 further illustrates that the control circuitry 120 may monitor properties of said reflected beam 110b, via a representation of the guided mode and emission pattern in a graph (or any other representation). In other aspects, the control circuitry may utilize graphs or other representations in within the control circuitry (at a backend thereof). The graph gl in Figure 1 illustrates backend monitoring from the control circuitry in which the graph gl illustrates two axis 9-axis and t-axis where 9-axis represent optical property changes (e.g. changes in refractive index of the sensing portion) and t-axis represent time. The graph gl illustrates in Figure 1 that a step occurs in the graph. The control circuitry may, based on said step / response in the graph gl, determine a presence, binding kinetics, affinity, and concentration of at least one specific analyte (under investigation) in the at least one sample.

[0052] Figure 1 further illustrates that the sensing portion 102 may be defined by a metal film, preferably gold, Au. Further, Figure 1 illustrates that the sample supply unit 104 may have at least one channel 104 in fluidic contact with said sensing portion 102. Further, the sample supply unit 102 may comprise an inlet 104b for each channel for introducing at least one sample to each corresponding channel 104a.

[0053] Furthermore, Figure 1 illustrates that the optical device 100 may be a layered structure. The light emitting and detecting unit 105 may be affixed / fixedly attached to a top surface tl of said transparent sensor substrate 101. Moreover, Figure 1 illustrates that the sensing portion 102 is affixed to an opposite bottom surface tl of the sensor substrate 101. As illustrated, the top and bottom surfaces tl, t2 are parallel. Advantageously a compact portable miniature structure is depicted. The optical device may have dimensions being lOxlOxlmm.

[0054] Figure 1 illustrates that the optical device 100 may form a block-like structure. Figure 1 illustrates that the sample supply unit 104 is at a bottom of said structure so that it, with the light-emitting and detecting unit 105 sandwiches the transparent sensor substrate 101.

[0055] The sample supply unit 104 together with the transparent sensor substrate 101 may be releasably attached to the light emitting and detecting unit 105, for example, via a releasable fixing mechanism. This allow the sample supply unit / transparent sensor substrate to be interchanged based on application. Moreover, it also enables a user to clean the film 102 after use. Thereby, increasing the lifetime of the optical device 100.

[0056] Figure 1 illustrates that the light source which may be a suitable laser device such as a verticalcavity surface-emitting laser and the detector are located on a common substantially flat surface. Moreover, Figure 1 illustrates that said at least one optical metasurface 106 is interfaced with the light-emitting and detecting unit 105 by being monolithically etched into a substrate of the light-emitting and detecting unit 106a. Nonetheless, in other aspects, not illustrated in Figure

[0057] 1, the optical metasurface 106 may be etched into a film deposited on a substrate of the light source 106a of the light-emitting and detecting unit 105 or etched into a film deposited on the transparent sensor substrate 101. Hence, the interfacing may be varied provided that the emitted beam 110a passes through the metasurface.

[0058] Figure 2 illustrates an objective view of said sample supply unit 104 being in the form of a microfluidic device. As illustrated in Figure 2, the sample supply unit 104 may comprise a plurality of channels 104b, each having a corresponding inlet 104a. In such a case the optical device 100 may comprise a corresponding amount of light sources, metasurfaces and detectors. Further, the sensing portion 102 may comprise a corresponding amount of films. In other aspects, the sensing portion 102 may comprise one film. Each channel 104b form / dimension may be varied in accordance with the knowledge of a skilled person in the art. Hence, the channels 104b are not limited to the meandering form as illustrated in Figure

[0059] 2.

[0060] Figure 3 illustrates a cut-out side view of the optical device 100 in which it is illustrated that the light detector 111 being part of the light-emitting and detecting unit 105 is an array of light scatterers affixed to a substrate of the light emitting and detecting unit 105. However, in other aspects, the detector 111 may be an optoelectronic light detector affixed to the substrate of the light emitting and detecting unit 105 or a photoluminescence material. The scatterers 111 may be dimensioned to scatter photons in a pattern which can provide information of the analyte. The control circuitry as illustrated in Figure 1 may process electrical signals from the detector so to monitor the analyte and determine characteristics thereof. The control circuitry may run a signal analysis algorithm so to monitor and determine characteristics thereof.

[0061] Figure 4 illustrates a method 200 for manufacturing the optical device of any aspect herein. The method 200 comprises the steps of providing 201 said transparent sensor substrate having a sensing portion (as shown in Figure 1). Further, the method comprises the step of providing 202 said light-emitting and detecting unit. Subsequently, the method 200 comprises forming 202 least one optical metasurface 106 on said light-emitting and detecting unit or said transparent sensor substrate, the at least one optical metasurface being dimensioned to produce a specific emission pattern 108 from said beam, the angular emission pattern 108 covering a set of angles required for generation of a guided mode at the sensing portion 102. Moreover, the method 200 comprises the steps of affixing 203 said light-emitting and detecting unit to said sensor substrate and attaching 204 an sample supply unit to said sensor substrate.

[0062] Figure 5 illustrates a method 200 for operating the optical device according to any aspect herein. The method 200 comprising the steps of.

[0063] Emitting 201, by the light source, a beam, through said transparent sensor substrate to the sensing portion, wherein said the at least one optical metasurface is dimensioned to produce an angular emission pattern from said emitted beam, the angular emission pattern covering a set of angles required for generation of a guided mode at the sensing portion;

[0064] Receiving 202, at the light-emitting and detecting unit, a reflected beam, the reflected beam being reflected via said sensing portion

[0065] Monitoring 203 by the light-emitting and detecting unit properties of said reflected beam, said properties being indicative of changes in optical properties of a sample at the surface of, or in the vicinity of, the sensing portion.

[0066] In some aspects, the method 200 may further comprise the step of determining 304, based on the monitoring 203, characteristics of one or more chemical compounds in said sample. The chemical compound may be a molecule, or any other particle, and characteristics may be concentration, presence, absence, and affinity.

Claims

CLAIMS1. An optical device (100) comprising:- a transparent sensor substrate (101) having a sensing portion (102), the sensing portion (102) being affixed to the transparent sensor substrate (101);- a sample supply unit (104) attached to the transparent sensor substrate, the sample supply unit (104) being arranged to introduce a sample onto the sensing portion (102);- a light-emitting and detecting unit (105) affixed to the sensor substrate (101);- at least one optical metasurface (106) interfaced with a at least one light source (106a) of said at least one light-emitting and detecting unit (105), wherein the optical device (100) is configured to: emit, by the light source (106a), a beam (110a), through said transparent sensor substrate (101) to the sensing portion (102), wherein said the at least one optical metasurface (106) is dimensioned to generate a specific emission pattern (108) from said emitted beam (110a), the angular emission pattern (108) covering a set of angles required for generation of a guided mode at the sensing portion (102) receive, at the light-emitting and detecting unit (105), a reflected beam (110b), the reflected beam (110b) being reflected via said sensing portion (102); monitor, by the light-emitting and detecting unit (105) properties of said reflected beam (110b), said properties being indicative of changes in optical properties of the sample at the surface of, or in the vicinity of, the sensing portion.

2. The optical device (100) according to claim 1, wherein the sensing portion (102) comprises at least one film layer deposited on the transparent sensor substrate (101), preferably, the film layer is a metal film.

3. The optical device (100) according to any one of the preceding claims, wherein the sample supply unit (104) is a microfluidic unit having at least one channel (104a) in fluidic contact with said sensing portion (102) and at least one inlet (104b) for introducing said sample to said channel (104a).

4. The optical device (100) according to any one of the preceding claims, wherein the light-emitting and detecting unit (105) is affixed to a top surface (tl) of said transparent sensor substrate (101), wherein the sensing portion (102) is affixed to an opposite bottom surface (tl) of said sensor substrate (101), wherein the top surface and the bottom surface (tl, t2) are parallel.

5. The optical device (100) according to any one of the preceding claims, wherein said at least one optical metasurface (106) is interfaced with the light-emitting and detecting unit (105) by being at least one of: monolithically etched into a substrate of the light source (106a) of the light-emitting and detecting unit (105); etched into a film deposited on said substrate of the light source (106a) of the lightemitting and detecting unit (105); etched into a film deposited on a substrate of the light-emitting and detecting unit (105); and etched into a film deposited on the transparent sensor substrate (101).

6. The optical device (100) according to any one of the preceding claims, wherein said light source (106a) comprises at least one vertical-cavity surface-emitting laser.

7. The optical device (100) according to any one of the preceding claims, wherein said light-emitting and detecting unit (105) comprises a light detector (111) for monitoring said properties.

8. The optical device (100) according to claim 7, wherein said light detector (111) is at least one of: an array of light scatterers affixed to a substrate of the light emitting and detecting unit (105) an optoelectronic light detector affixed to the substrate of the light emitting and detecting unit (105); anda photoluminescence material.

9. The optical device (100) according to any one of the preceding claims, wherein the at least one metasurface (106) is a metagrating, preferably an offset-axicon based metagrating, producing an angular emission pattern required for generation of a surface plasmon mode10. A method (200) for manufacturing the optical device of any one of the claims 1-9, comprising the steps of: providing (201) said transparent sensor substrate having a sensing portion; providing (202) said light-emitting and detecting unit; forming (203) least one optical metasurface (107) on said light-emitting and detecting unit or said transparent sensor substrate, the at least one optical metasurface being dimensioned to produce an angular emission pattern (108) from said beam, the angular emission pattern (108) covering a set of angles required for generation of an optical property-altering waveguided mode at the sensing portion (102) affixing (204) said light-emitting and detecting unit to said sensor substrate; attaching (205) a sample supply unit to said sensor substrate.

Images