Apparatus and method comprising metadevice and photonics-based biosensing - Patent Application 20070123633

Abstract

In certain embodiments, the methods, semiconductor structures, and aspects of the present disclosure include a guided-mode resonant metasurface biosensor pixel ("GMR pixel") having a cavity portion that supports GMR at a specific Q and optics on either side of the GMR pixel to confine light and mitigate energy loss due to light scattering in response to light directed at the GMR pixel of the metasurface sensor. In certain more specific embodiments, exemplary aspects of the present disclosure are directed to a functionalized metasurface sensor that includes an array of guided-mode resonant metasurface biosensor pixels, each pixel functionalized for attachment of a distinct receptor or probe molecule.

Description

[Technical field]

[0001] In a particular exemplary context, aspects of the present disclosure are directed to apparatus and methods comprising guided mode resonant metasurface pixel structures and designs with aspects of assisting GMR at particular quality factors, including analysis of biomolecules and chemical species associated with the genome, proteome, transcriptome, epigenome, metabolome, and / or microbiome, which are important for understanding, monitoring, and treating the health of organisms and ecosystems. Integrating data from multiple biomarkers, such as both nucleic acids and proteins, from a single sample or specimen can provide deeper insight into complex biological processes or genotype-phenotype-environment relationships than analysis of individual biomarkers alone.

[0002] Providing efficient, cost-effective and convenient devices and / or methods for such analysis is difficult. Moreover, attempting to analyze a large number of biomarkers and / or multiple classes of biomarkers in such a method is complex and burdensome, which poses challenges in various clinical and research applications. [Background technology]

[0003] Various examples / embodiments provided by this disclosure address the above challenges and / or other challenges that may become apparent from the following disclosure. For example, some of these disclosed aspects are directed to methods and apparatus that use or utilize energy moderation or optimization. In certain examples, samples are manipulated with biological material and then treated with distinct receptors or probe molecules to detect distinct aspects of the sample.

[0004] In certain embodiments, methods and devices (e.g., electronic devices) include a guided-mode resonant metasurface biosensor pixel ("GMR pixel") having a cavity portion that supports GMR at a particular Q and optics on either side of the GMR pixel to confine light and mitigate energy loss due to light scattering in response to light directed at the GMR pixel of the metasurface sensor. In certain more specific embodiments, exemplary aspects of the present disclosure are directed to a functionalized metasurface sensor that includes an array of guided-mode resonant metasurface biosensor pixels, each pixel functionalized for attachment of a distinct receptor or probe molecule.

[0005] In other more specific exemplary aspects of the present disclosure (which may be related to or based on one or more of the above methods and apparatus), such a functionalized metasurface sensor may include an array of high-Q guided mode resonant metasurface biosensor pixels ("GMR pixels"), each pixel functionalized to attach at least one distinct receptor and / or at least one set of probe molecules. Each GMR pixel, which may be energized by directed light, may have optics on either side of a cavity portion, which act as photonic mirrors to prevent energy leakage and reflect energy towards the cavity portion.

[0006] In more specific aspects that may be related to or based on the above aspects, the present disclosure is directed to: devices partially or fully manufactured as in the exemplary aspects and embodiments as described or characterized herein; methods of using the devices (e.g., in testing, measurement, and / or research / clinical settings) as described or characterized herein; and methods of manufacturing devices partially or fully manufactured as described or characterized herein.

[0007] In more specific embodiments that may also be based on embodiments described herein, the aspects include the following: the blocks of the GMR pixel are responsive to light directed at a surface of the GMR pixel, causing the formation of a photonic bandgap, where photonic modes with frequencies within the bandgap are not allowed to propagate, and frequencies corresponding to the edges of the bandgap are tuned based on the dimensions of the nanoblocks; the optical system includes a first set of one or more nanoblocks and a second set of one or more nanoblocks at opposite ends of the GMR pixel and the cavity portion; the optical system functions or acts as a photonic mirror by including a resonant mode; the cavity portion has nanoblocks of different dimensions, where one different dimension is distinguishable from another different dimension by the length of the nanoblocks; the cavity portion is configurable according to design and application. and wherein the cavity portion has a plurality of nanoblocks of different lengths, the different lengths being dimensioned such that ends of the plurality of nanoblocks collectively align to form at least a portion of a tapered dimension between ends of the optical system (e.g., as shown in FIG. 6 ); the cavity portion has a plurality of nanoblocks of different dimensions, one different dimension being distinguishable from another different dimension by the length of the nanoblock; and at least one of the GMR pixels has a material that can be energized by light directed thereto, and has at least one portion with a length corresponding to an illumination wavelength energy that is less than the band gap of the material.

[0008] In one particular embodiment, the present disclosure is directed to a method having certain aspects of the above aspects disclosed herein for the device. For example, one such method according to the present disclosure includes functionalizing a metasurface sensor and / or fixing an optical system to each end of a plurality of GMR pixels. The step of functionalizing the metasurface sensor relates to a metasurface sensor characterized to include an array of (e.g., high-Q) guided mode resonant metasurface biosensor pixels ("GMR pixels") by attaching a distinct receptor or probe molecule to each of the GMR pixels. Fixing an optical system to each end of the plurality of GMR pixels optimally mitigates light trapping, energy loss due to light scattering in response to light directed to the metasurface sensor. In this approach described above, the circuitry and functionalization allows the directed light to be scanned by a biological sample, thereby allowing different types of biological molecules in the biological sample to be distinguished at the GMR pixels.

[0009] In more specific embodiments, the method further includes distinguishing between different types of biological molecules in a biological sample; and / or using a circuit to direct light towards the metasurface sensor, the circuit comprising a CCD and logic circuitry responsive to the directed light.

[0010] In further related embodiments applicable to the above types of methods, the method may include patterning distinct receptor or probe molecules on each GMR pixel via acoustic droplet ejection and / or customizing or matching the surface functionalization resolution of each and every GMR pixel to detect distinct biomarkers for adjacent ones of the GMR pixels or for specific distinct target species of the sample for analysis.

[0011] In a further embodiment of the above type of method, separate receptor or probe molecules may be attached to the surface of the GMR pixel by applying a material that minimizes non-specific adsorption for binding to the antibody of interest.

[0012] In more specific examples of the above methods and / or devices, an electronic device (e.g., part of such a device) may include separate receptor or probe molecules for attachment to each one of the metasurface biosensor pixels.

[0013] According to other related aspects that may be based on one or more of the above embodiments and aspects, the present disclosure is directed to a bioprinted metasurface biosensor pixel.

[0014] According to yet another related aspect, the present disclosure is directed to one or more aesthetic or decorative design aspects (e.g., pixel structures and / or metasurface arrays) characterized by one or more of the structures shown in the drawings herein.

[0015] The above description is not intended to describe each aspect, embodiment, or every implementation of the present disclosure. The following figures and detailed description also illustrate various embodiments.

[0016] Various example embodiments, including experimental examples, of the present disclosure may be more fully understood in consideration of the following detailed description taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 illustrates the calculated Q-factor as a function of structural perturbation Δd for an infinitely long resonator (solid straight black line), a waveguide device truncated to 10 μm (solid curved blue line), and the total quality factor (horizontal dashed red line) is limited by the maximum quality factor associated with scattering losses, in accordance with the present disclosure.

[0018] [Diagram 2] 2A and 2B are related graphs of the change in length of a silicon nanoblock along a waveguide affecting the shift of the bandgap to different (lower) frequencies, in accordance with the present disclosure.

[0019] [Diagram 3] FIG. 3A shows an infinitely long sensing pixel design and associated graph of Q-factor versus Δd (nanometers) according to the present disclosure, where the pixel design includes blocks of two different lengths (length is the horizontal dimension) that support GMR at a particular high Q, and shows a cavity portion at each end with an optical portion that includes at least one (e.g., five) blocks of similar length.

[0020] [Diagram 3] FIG. 3B illustrates an example of the sensing pixel design of FIG. 3A in a perspective view of a substrate structure with a top surface to which at least one block of pixels is secured, according to the present disclosure.

[0021] [Figure 4] FIG. 4 (with its associated dual set of graphs and equations for calculating mirror strengths according to the present disclosure) illustrates how use of such an exemplary sensing pixel design type can increase the Q by up to an order of magnitude compared to a device that does not have a mirror element to contain a guided mode resonance within the waveguide.

[0022] [Diagram 5] FIG. 5 shows an example pixel design (with dimensions in microns along the X and Y axes) that helps visualize such an order of magnitude increase in Q (from ∼8000 to ∼80000) according to certain specific embodiments of the present disclosure.

[0023] [Figure 6] FIG. 6 shows an example scanning electron microscope image of another similarly constructed example high-Q pixel structure (e.g., having a cavity portion with blocks collectively aligned to form a tapered dimension having a length of ∼10 μm and a block at the end of one pixel that provides the optics for reflecting light) according to certain specific embodiments of the present disclosure.

[0024] [Figure 7]FIG. 7A shows how the spectral response of multiple pixels (as illustrated in the example of FIG. 6) can be measured simultaneously through the intensity at each pixel's location.

[0025] [Figure 7] FIG. 7B shows an image corresponding to a multiplexed metasurface functionalized using droplet generation or chemical transfer for surface functionalization at the resolution of an exemplary patterned metasurface.

[0026] [Figure 8] FIG. 8B is a perspective view of a sensor system including an array of GMR pixels in accordance with the present disclosure.

[0027] While the various embodiments described herein are amenable to modification and alternative forms, aspects thereof are shown by way of example in the drawings and will be described in detail. However, it is understood that there is no intention to limit the disclosure to the specific embodiments described. Rather, the intention is to cover all modifications, equivalents, and alternatives within the scope of the disclosure, including aspects defined in the claims. In addition, the term "exemplary embodiment" as used throughout this application is for illustrative purposes only and not limiting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Aspects of the present disclosure are believed to be applicable to a variety of different types of devices, systems, and methods including optical metastructures and / or metasurfaces (often collectively referred to as "metadevices") with nanostructured silicon blocks and / or films, which may have many applications depending on the design. According to an example of one particular aspect of the present disclosure, such an optical metadevice detects surface binding of a biomarker by involving guided mode resonance (GMR) supported by each metasurface that resonantly traps light along the patterned silicon nanostructures and / or by the cavity portion of each pixel designed for the metadevice. This particular aspect of surface binding of a biomarker illustrates one of the other particular aspects of the present disclosure, which may benefit from one or more metadevices having multiple nanostructures thereon that collectively function or act as a set of photonic mirrors that include resonant modes associated with one or more GMRs for the light manipulated by the metadevice. This type of design is particularly beneficial for relatively short (or shortened) sensor devices. Although the following description refers to the aspects as illustrated in particular devices and methods, such description is merely intended to provide an exemplary context to aid in the description of one or more aspects and does not necessarily limit the disclosure.

[0029] According to a specific example embodiment, where such optical metadevices are used for surface binding of biomarkers according to the present disclosure by supporting high Q GMR for light scanned by the waveguide using one or more metadevices with multiple nanostructures, this type of design is particularly beneficial for relatively short (or shortened) sensor devices, since there is no significant loss at high Q and losses due to scattering from the ends of the waveguide are minimized. In a more specific configuration, multiple nanostructures (or blocks) are utilized at the ends of each pixel to act as photonic mirrors, so that light is reflected back towards the center (cavity portion) and contains a high Q resonant mode within the relatively short sensor device.

[0030] In certain specific examples, there is significant Bragg scattering along the waveguide device due to the significant refractive index contrast between the silicon nanostructures and the surrounding medium. This creates a photonic bandgap where photonic modes with frequencies within the bandgap do not propagate. In certain more specific aspects of the present disclosure, the frequency corresponding to the edge of the bandgap can be tuned by varying the dimensions of the blocks along the waveguide chain.

[0031] Thus, in the following description, various specific details are set forth to explain the specific examples presented herein. However, it will be apparent to one of ordinary skill in the art that one or more other examples and / or variations of these examples may be practiced without all of the specific details set forth below. In other instances, well-known features are not described in detail so as not to obscure the description of the examples herein. For ease of illustration, the same symbols and / or reference numbers may be used to refer to the same elements or additional instances of the same elements in different figures. Also, although aspects and features may in some cases be described in separate figures, it is understood that features from one figure or embodiment may be combined with features from another figure or embodiment, even if the combination is not explicitly shown or described as a combination.

[0032] Moreover, certain aspects of the present disclosure are directed not only to fully fabricated devices as in the exemplary aspects and embodiments as may be described or characterized in certain portions of this disclosure, but also to aspects of partially fabricated devices and / or elements of devices (e.g., optical or photonic mirrors, high-Q pixel structures, metasurface arrays, etc.) that are assembled into and included in more complete devices consistent with certain exemplary aspects and embodiments described or characterized herein. Certain other aspects of the present disclosure are also directed to methods of using such devices (or elements thereof) (e.g., in testing, measuring, and / or research / clinical settings).

[0033] An example embodiment of the present disclosure is directed to a method and apparatus that includes energy optimization to detect distinct aspects of a sample manipulated by a biological sample and then treated with distinct receptor or probe molecules. In a specific embodiment, the method and semiconductor structure are directed to a functionalized metasurface sensor that includes an array of high-Q guided mode resonant metasurface biosensor pixels ("GMR pixels"), each functionalized for attachment of at least one distinct receptor or probe molecule. An optical system is coupled to each end of the GMR pixels to confine the sample manipulated light (by the biological sample) and optimally mitigate energy loss due to light scattering, and further, a light response circuit and a data processing circuit respond to the sample manipulated light by each one of the distinct receptor or probe molecules to distinguish different types of biological molecules in the biological sample. One or more of the GMR pixels may have a material that can be energized by directed light and have at least one portion having a length corresponding to an illumination wavelength energy less than the bandgap of the material, and at least one of the GMR pixels may have an optical system including a cavity portion and a set of one or more blocks on either side of the cavity portion that act as photonic mirrors (e.g., to mitigate or prevent energy loss due to scattering of the light by directing energy into the cavity portion).

[0034] Aspects of various embodiments are directed to apparatus (e.g., systems, devices, assemblies, components, materials, etc.) as described in the claims, specification, and drawings, and any of various types of processes (e.g., methods of use and methods of manufacture) involving one or more of such apparatus. For information regarding details of other embodiments, experiments, and applications that can be combined to various degrees with the teachings of this specification, reference may be made to the teachings and underlying references disclosed in U.S. Provisional Application No. 63 / 283037 (STFD.438P1 S21-418), filed November 24, 2021, from which priority is claimed (with appendices), and, to the extent permitted, such subject matter is incorporated by reference in its entirety, and specifically for further examples and more detailed embodiments that may be useful in supplementing and / or clarifying.

[0035] In certain more specific example embodiments, the present disclosure is directed to an optical platform for rapid, label-free, high throughput, and multiplexed biomarker analysis. The platform can detect multiple distinct DNA and RNA sequences, along with distinct proteins, from a single sample on a single chip without relying on the recognition of any fluorescent or optical tags. In certain more specific aspects, the present disclosure is directed to providing a small, fast, potentially low-cost platform for targeted DNA and RNA sequencing, where thousands of distinct nucleic acid probe sequences may be arrayed across an exemplary sensing device for multiplexed genetic and transcriptomic analysis. Furthermore, proteins and metabolites can also be detected on the same platform, enabling multi-omics data sets for determining genotype-phenotype-environment associations. Such aspects enable the acquisition of big data to improve early detection of disease, treatment monitoring of cancer and infectious diseases, understanding the progression of neurological diseases, detection of toxins in agricultural and environmental settings, etc.

[0036] In certain more specific example embodiments, aspects of the disclosure are directed to methods for use in systems where nanophotonics waveguide-based devices exhibit radiative losses, where the devices account for or mitigate the reduction in Q-factor associated with photons scattering from truncated ends of the waveguide. Certain more specific related embodiments are directed to devices or methods that comprise or include high quality (high Q) factor metasurfaces, where Q is at least several thousand, and in some cases greater than 1000 or greater than 10,000 (e.g., ∼12,000, ∼15,000, ∼20,000, or more), for use with biosensing samples, such as those associated with detection of nucleic acids, proteins, pathogens, and small molecules. In another example, the high Q is characterized as being in the range of 1000 to 40,000 or 60,000. In such embodiments, the one or more photonic mirror elements aid in spatially confining guided mode resonance (GMR) and / or preventing scattering losses; the use of such photonic mirrors is used in conjunction with reduced metasurface device dimensions to generate small, individually addressable biosensing pixels; and / or the design is directed to one or more aesthetic or decorative design aspects of the structures shown in the drawings herein (e.g., one or more combinations of high-Q pixel structures and / or arrays of such structures as shown in conjunction with the metasurface).

[0037] In further specific aspects, the present disclosure is directed to one of the following utilized or embodied individually or in combination of two or more of the following: (a) high-Q pixel sensing element designs comprising metasurface design features that enable truncation and shrink the resonating device to a relatively small footprint sufficient to enable densely patterned individually addressable sensing devices and / or enable high-density microarrays of sensing elements that can act as a platform for massively multiplexed and parallelized biomarker detection; (b) free-space emission control and high emission Q-factor; (c) photonic mirrors that mitigate loss of Q due to edge scattering; (d) fabrication and optical characterization of metasurface arrays; (e) metasurface functionalization and multiplexed functionalization methods; (f) multiplexed metasurface functionalization; (g) metasurface functionalization for protein detection; and (h) acoustic bioprinting of such metasurface-related aspects or designs (each such aspect is exemplified without limitation with respect to other examples presented herein).

[0038] With respect to more specific examples consistent with certain of the above aspects, such fabricated devices or fabrication methods may include bioprinting (e.g., acoustic bioprinting) of such metasurface-related aspects or designs. According to other related aspects, the present disclosure may be directed to or include printing-based surface functionalization of chip surfaces. With respect to these aspects, bioprinting is utilized to attach distinct receptor molecules to individual metasurface biosensor pixels. The small droplet size of bioprinting allows for spatial patterning of arrays of sensing pixels, where individual pixels may be tuned to detect distinct biomarkers from adjacent pixel elements.

[0039] In certain specific example embodiments according to the present disclosure, acoustic bioprinting methods are used to provide groups of chemically or biologically functionalized biosensors or individual resonators with unique surface functionalization. One form of acoustic printing uses focused acoustic waves to eject droplets without the use of a focusing nozzle. Thus, the droplet diameter is a function of the resonant frequency of the acoustic transducer, which is inversely proportional to the resonant frequency. Thus, the droplet volume can be varied by changing the resonant frequency of the printer. In a further specific experimental proof-of-concept effort related to the present disclosure, the inventors have demonstrated stable biological printing with four resonant frequencies varying from 5 MHz to 147 MHz generating droplets with diameters from 300 μm to 15 μm or volumes from 4.5 nL to 2 pL (demonstrated in slide 1 of the accompanying slides). The printer may be used to print and deposit an array of biological functionalizations onto the chip (as shown in Figures 3B, 6 and 8). The printer may be used with different chemistries to deposit an antibody onto the GMR / resonator array and measure the shift in resonator frequency due to binding of this probe antibody along with a protein of interest (e.g., the receptor binding domain of the COVID spike protein) incubated on the chip. For these efforts, it was demonstrated that such a printer may be used to deposit 2 picoliter droplets onto a single biosensor pixel, again using fluorescently tagged proteins.

[0040] Consistent with the present disclosure, such devices and / or methods may be used to fabricate devices as characterized above that include functionalized metasurface sensors, optics, and light-responsive data processing circuitry that are cooperatively configured to detect multiple distinct DNA and RNA sequences, along with distinct proteins, from a single sample on a single chip without relying on recognition of any fluorescent or optical tags (among other examples disclosed herein). Additionally, distinct receptor or probe molecules may be configured for attachment, and in some implementations, attached to each of the metasurface biosensor pixels. In certain applications, such devices may be used to detect and distinguish different types of biological molecules, including one or more of nucleic acids, proteins, pathogens, and small molecules.

[0041] Certain specific aspects of the present disclosure are directed to or include high-Q sensing element designs that utilize optical metasurfaces that include or consist of nanostructured silicon films to detect surface binding of biomarkers. These metasurfaces resonantly trap light along patterned silicon nanostructures, resulting in strong electromagnetic field concentration and sharp scattering spectra due to GMR. The GMR is excited via free-space illumination from a laser or light-emitting diode, and the scattered light is directed to a camera sensor. According to certain metasurface design features developed in a manner consistent with the present disclosure, such high-Q sensing aspects truncate the resonant device, shrink it to a small footprint, and enable individually addressable sensing devices patterned at densities of over one million elements per square centimeter. These design features enable high-density microarrays of sensing elements that can act as a platform for massively multiplexed and parallelized biomarker detection.

[0042] Related to the above, according to more specific aspects, the present disclosure is directed to or includes high-Q commentary optical metasurfaces or high quality factor metasurfaces for use in connection with various types of biosensing, including, by way of example, direct detection of nucleic acids, proteins, pathogens, and small molecules. Such more specific aspects exploit and / or include the use of photonic mirror elements that spatially confine GMR and prevent scattering losses when scaling down the dimensions of the metasurface device to create small, individually addressable biosensing pixels. Furthermore, when combined with conventional (e.g., CMOS-based) fabrication processes, metasurface sensing elements according to the present disclosure can be patterned at densities exceeding hundreds of elements per square centimeter, and in some cases, many (e.g., hundreds, hundreds, or millions) of elements per square centimeter. Due to the sharp scattering from the high-Q resonances, optical tagging of the molecules of interest is not required (although it may be used), and instead molecular binding is sensitively detected through changes in scattered light intensity from each pixel. High-density sensor arrays allow for the acquisition of rich data sets from a single image.

[0043] The description now turns to various more specific examples of the present disclosure, presented with figures to illustrate certain more specific (e.g., experimental / conceptual) aspects and embodiments. Thus, as primarily characterized above, such examples of the present disclosure are directed to different types of devices including guided mode resonant metasurface pixels ("GMR pixels") with optics at both ends of the GMR pixel, having a cavity portion that aids GMR at a specific Q to confine light and mitigate energy loss due to light scattering in response to light directed at the GMR pixel of the metasurface sensor. More specific examples of the present disclosure are directed to devices having high-Q pixel sensing element designs with metasurface design features that allow for truncation and shrinking of the resonant device to a smaller footprint, enabling individual patterned addressable sensing devices at high density (e.g., 100 to over 1 million elements per square centimeter), and / or enabling high density microarrays of sensing elements that can act as a platform for massively multiplexed and parallelized biomarker detection.

[0044] According to a particular experimental metasurface design, chains of nanostructure blocks are patterned in high refractive index materials such as silicon, silicon nitride, gallium nitride, titanium dioxide, and / or hafnium dioxide. One-dimensional chains of nanostructures may constitute a waveguide supporting guided modes localized along the length of the nanopatterned chain. Structural perturbations are included in the longitudinal direction of the waveguide device, enabling free-space coupling at high-Q guided mode resonances. Structural perturbations along the chain can directly control the quality factor associated with the radiative losses of the mode as photons coupled in the GMR are eventually re-radiated back into free space. However, the overall quality factor of a photonic mode is considered as a combination of all relevant photon loss mechanisms of the nanophotonic device. In the context of the present disclosure, considering a waveguide device that is infinitely long (or much longer than the photonic mode propagation length) and operates with illumination wavelength energies below the band gap of the material that constitutes the nanophotonic device (thus reducing material absorption to a negligible fraction or zero), only radiative losses are considered relevant for the sensor design and can be controlled by geometric perturbations as described above. However, as the length of the waveguide device is shortened to construct smaller sensing pixels, such as those required to create high-density microarrays of individual sensing elements, the Q factor associated with photons scattering from the truncated ends of the waveguide is considered. As the length of the waveguide device is shortened, the guided mode resonances are increasingly scattered from the boundaries of the ends of the waveguide, reducing the overall Q factor and performance of the sensor. Therefore, additional design elements not previously considered may be used to facilitate high-Q small sensing pixels.

[0045] 1, the calculated Q-factor is shown as a function of structural perturbation Δd for an infinitely long resonator, indicated by the solid black line 110, and for a waveguide device truncated to 10 μm, indicated by the solid blue line 120. Due to scattering from the truncated ends of the shortened structure, the total quality factor is limited by a maximum quality factor related to the scattering losses, indicated by the dashed line 130.

[0046] To minimize losses due to scattering from the ends of the waveguide, additional nanostructures are utilized that act as photonic mirrors that confine the resonant modes within the shortened sensing device. Due to the significant refractive index contrast between the silicon nanostructures and the surrounding medium, there is significant Bragg scattering along the waveguide device. This creates a photonic bandgap, where photonic modes with frequencies within the bandgap do not propagate. By varying the dimensions of the blocks along the waveguide chain, the frequency corresponding to the end of the bandgap can be tuned.

[0047] 2A and 2B are related graphs showing how exemplary silicon nanoblocks on a structure can be effectively increased to shift the band gap to lower frequencies in terms of the change in length of the silicon nanoblocks along the waveguide, according to aspects of the present disclosure. More specifically, FIGs. 2A and 2B show frequency vs. band gap plots illustrating the behavior of a chain of silicon blocks with specific structural features, including how the dimensions can be adjusted to move the position of the band structure to different frequencies, for an example of the structure.

[0048] More specifically, the plots corresponding to the (blue) lines 215, 215', and 220 in Figures 2A and 2B show the band structure of a chain of silicon blocks corresponding to a particular structure (e.g., having a height of 600 nm, a width of 160 nm, a length of 600 nm, and a spacing of 330 nm). The absolute dimensions may be adjusted to shift the position of the band structure to different frequencies. The (red) lines 216 and 216' in Figure 2A show the optical response of a photonic mirror-like segment with long blocks (similar to the light-containing optics in the schematic diagram of Figure 3A below), where each block has a length dimension of ∼1300 nm (all other dimensions are fixed), and show the band structure of a similar chain of silicon blocks resulting in a shift in frequency from the blue lines. Since the blue line 215' in FIG. 2A has a resonant mode at a frequency within the bandgap of the red lines (216 and 216') band structure, blocks of these two different dimensions (shorter 600 nm, longer 1300 nm) may be used to construct a high-Q pixel resonator as shown diagrammatically in FIG. 3A.

[0049] According to the present disclosure, by designing a sensing pixel with sections having two different block lengths, it is possible to design a cavity section with a resonant mode corresponding to a band-edge state and a mirror section with a band gap shift such that the mode frequency of the cavity section is located within the mirror band gap. The mirror sections at both ends of the resonator serve to prevent the scattering of the guided mode resonance from both ends of the waveguide and instead reflect the mode back into the cavity section. Furthermore, the mirror strength may be systematically designed to optimally localize the photonics mode within the resonator by tapering the mirror sections to create a linearly varying mirror strength profile.

[0050] FIG. 3A shows an example of a sensing pixel design and associated graph of Q-factor versus Δd (nanometers), where the Q-factor is for an infinitely long chain constructed of silicon blocks versus a short finite chain. As illustrated in these plots in FIG. 3A, without the use of photonic mirror structures, as in the embodiments of the present disclosure, the Q-factor of the resonator device drops off rapidly as the physical size of the device is reduced. However, by adding such photonic mirror elements to the end of the pixel device, a high Q-factor is maintained even in small devices (e.g., on the order of 10-20 μm).

[0051] Figure 3B shows a perspective view of the example sense pixel design of Figure 3A, showing a substrate structure with a first surface to which at least one block of pixels is fixed (an array of pixels may be fixed), a first long side on the left side (which may have the same appearance as the opposite side), and a second short side near the bottom of the sheet (which may have the same appearance as the opposite side at the top). The view of the example sense pixel design of Figure 3A (and similar structures on the left and right of Figure 6, which show different surfaces showing different block lengths) is useful for illustrating the aesthetic aspects of such designs according to the present disclosure.

[0052] FIG. 4 (with its associated dual set of graphs and equations for calculating mirror strengths according to the present disclosure) shows how use of such an exemplary sensing pixel design type can increase the Q by up to an order of magnitude compared to a device that does not have a mirror element to contain a guided mode resonance within the waveguide.

[0053] As shown by way of example in FIG. 5, this design strategy can increase the Q by an order of magnitude compared to a device that does not have mirror elements to contain guided mode resonances within the waveguide (the example scale to the right of each such device characteristic in FIG. 5 is from −2500 to 2500).

[0054] The metasurface pixels are fabricated in a silicon membrane on a transparent sapphire substrate using electron beam lithography. Figure 6 shows a scanning electron micrograph of the fabricated high-Q pixel structure with a length of 10 μm. Due to the spatial localization of the resonant modes, in this exemplary embodiment, each pixel is 30 μm long. 2 The nanostructures require only a footprint of 1000 nm. This small footprint allows pixel densities of up to 3 million features per square centimeter. When illuminated at normal incidence from free space, the nanostructures strongly scatter transmitted and reflected light towards a camera detector. The spectral response of multiple pixels can be measured simultaneously through the intensity at each pixel's location, as seen in Figure 7A, where bright spots represent the scattering signal from individual resonators.

[0055] Exemplary metasurface functionalization allows selective target binding and detection. To realize the multiplexing capabilities of such devices, the surface is functionalized to attach distinct receptor or probe molecules to individual metasurface biosensor pixels while simultaneously preventing non-specific binding on the surface. Furthermore, the use of surface functionalization chemistries and patterning methodologies is effective to enable the functionalization of individual resonators with arrays of probe molecules that allow the detection of nucleic acids, proteins, whole pathogens, and / or small molecules on a single chip. Chemical functionalization of the surface relies on covalent silanization of the metasurface with, for example, (3-aminopropyl)trimethoxysilane (APTMS) or 11-aminoundecyltriethoxysilane (AUTES). Amine-sulfhydryl bridging with m-maleimidobenzoyl-N-hydroxysuccinimide (MBS) ester is then used to attach the thiolated molecules required for probe binding. These initial steps can be performed in bulk across the entire multiplexed chip.

[0056] For massively multiplexed biomolecular detection, individual functionalization of each resonator is performed. In one example, an (integrated circuit) chip is utilized for 1) multiplexed detection of multiple biomarkers from a single sample, or 2) detection of a single biomarker from multiple samples.

[0057] For multiplexed detection of an array of biomarkers, picoliter to microliter quantities of distinct receptor molecules are attached to individual metasurface biosensor pixels and flowed over a single biological sample for analysis. Conversely, for multiplexed detection of a single biomarker in one step, the surface is globally functionalized with a single probe molecule and picoliter to microliter quantities of distinct samples are deposited on the exemplary chip.

[0058] In one embodiment, acoustic bioprinting (acoustic droplet ejection) is used to pattern the probe molecules. Acoustic printing works by using ultrasound to eject droplets from the free surface of a fluid. A radio frequency (RF) burst signal is used to excite a transducer at its resonant frequency, generating ultrasound waves that exert a force on the liquid surface. When the focus of the transducer coincides with the liquid-air interface and the intensity of the acoustic field is high enough, the generated radiation pressure becomes greater than the surface tension forces, and droplets are ejected from the fluid surface due to Rayleigh-Taylor instability. The diameter of the ejected droplets is inversely proportional to the frequency of the transducer, with 5 MHz and 300 MHz ultrasound producing droplet diameters of 300 μm and 5 μm, respectively. The size, velocity, and directionality of the ejected droplets are fully controlled by the acoustic waves, without the need for a physical nozzle as in other commercially available piezo and thermal inkjet printers. As a nozzle-free technology, acoustic droplet ejection has unique advantages in handling biological samples, especially eliminating clogging, sample contamination, cell viability, and degradation of biomarker structure due to shear forces from the nozzle. Moreover, acoustic droplet ejection (ADE) enables high-throughput droplet generation, processing liquids at speeds up to 25 kHz with a single ejection head. Moreover, because the platform relies on acoustic waves, these waves can propagate through compatible coupling media with minimal loss of acoustic energy, avoiding sample contamination and maintaining sterility.

[0059] According to another exemplary aspect of the present disclosure, the small droplet sizes (picoliters to microliters) generated using acoustic bioprinting allow for the spatial resolution and patterning of exemplary pixel arrays to be matched with the resolution of surface functionalization, such that individual pixels can be tuned to detect distinct biomarkers from adjacent elements or from separate patient samples for analysis.

[0060] It will be appreciated that such multiplexed metasurfaces may be functionalized using any droplet generation or chemical transfer method that allows for surface functionalization at the resolution of the exemplary patterned metasurfaces. Other embodiments include, but are not limited to, inkjet printing, nanocontact print stamping, microcontact printing, and pipetting.

[0061] One such example is shown in Figure 7B, where bioprinting provides such functionalization (e.g., using a millimeter scale) via precisely positioned droplets containing different analytes with physical dimensions of 10-100 μm. In a specific example experiment, multiplexed biomolecular detection is possible by bioprinting different chemicals in close proximity to the physical dimensions (~10s of microns) of individual optical resonator devices.

[0062] In a specific further experimental example involving metasurface functionalization for nucleic acid detection, complementary nucleic acid sequences can be used as probe molecules for surface functionalization. After functionalization with MBS, thiolated nucleic acid probes with sequences complementary to the target molecule are attached to the surface. The probe concentration and surface density can be adjusted to maximize hybridization efficiency with the target nucleic acid strand by diluting the initial silane self-assembled monolayer with 10P TMS (trimethoxy(propyl)silane). This well-studied surface functionalization approach via silanization has already been validated for reproducible and controllable oligonucleotide attachment in the context of the present disclosure.

[0063] After completion of the overall functionalization with exemplary silane molecules and MBS, one such method of preparation then attaches the probe molecules to the surface. In one embodiment, the surface is functionalized with a monolayer of a zwitterionic polyethylene glycol (PEG)-ylated matrix optimized to minimize non-specific adsorption. This matrix is ​​composed of an optimized ratio of two molecules of 2-{2-[2-(1-mercaptoundec-11-yloxy)-ethoxy]-ethoxy}-ethoxynitrilotriacetic acid (HS-C11-(EG)3-NTA) and (2-[2-(2-[11-mercaptoundecyloxy)-ethoxy]-ethoxy]-ethoxy]-ethoxy)dimethylammonio)acetate, the first of which will ultimately bind the antibody of interest and the second of which will increase the density of the monolayer. The NTA molecules are then bound by incubation with nickel chloride salt. This Ni(II)-NTA complex then allows binding of the RBD region of the SARS-CoV-2 spike protein to the exemplary metasurface. The spike protein was modified with a polyhistidine tag to improve the affinity of the spike protein for metal ions, thereby improving the binding affinity of the exemplary monolayer with the Ni(II)-NTA complex. Importantly, this functionalization orients the antibody recognition site, improving the binding potential of the primary antibody. In another embodiment, the surface is functionalized with thiolated biotin polyethylene glycol (PEG) and then incubated with streptavidin protein. After incubation with streptavidin molecules, the chip is incubated with a probe molecule that is biotinylated or modified to covalently bind to the protein, allowing it to specifically bind to the streptavidin-terminated surface monolayer. Once surface functionalization to construct a self-assembled monolayer with the probe molecules is complete, the chip is placed in a sealed holder, such as a PDMS fluid cell, allowing a patient liquid sample (e.g., blood, serum, plasma, urine, saliva, etc.) to be introduced onto the chip without contamination, allowing simultaneous optical interrogation and readout, as well as monitoring of the kinetic binding response of the system.

[0064] In relation to specific examples and specific applications, aspects of the present disclosure find application in clinical and research settings for diagnosing and monitoring the health of humans, animals, and ecosystems. For example, detecting many genetic mutations and protein signatures in parallel is important for treating various cancers, cardiovascular diseases, and neurological diseases. Identifying both metabolites and environmental DNA and proteins is often important for monitoring marine biodiversity and the spread of marine toxins. In accordance with the present disclosure, certain platform-based aspects enable multi-biomarker related studies for a better understanding of diseases that were previously unavailable due to the limitations of measuring multiple analytes in a single sample. In an exemplary clinical setting, other aspects of the present disclosure provide a rapid, low-cost device that generates longitudinal data of biomarker or metabolite levels relevant to treatment regimens, allowing for rapid adjustment or optimization of a patient's treatment regimen.

[0065] In certain contexts, advantages and improvements over existing methods, devices, or materials include massive multiplexing capabilities with sensing elements patterned at densities exceeding 1,000,000 features per square cm, and the possibility to analyze multiple classes of biomarkers (e.g., both nucleic acids and proteins) on a single chip for more accurate or earlier diagnosis. Multiplexed detection of genes and proteins can also be rapidly performed with much higher throughput than PCR, ELISA, mass spectrometry, and other methods. Metasurface elements exhibit sharp scattering spectra that sensitively change upon binding of the biomarkers of interest to the silicon surface, negating the need for an optical tagging step that requires additional processing and expensive reagents. Since no amplification and tagging are required, sample processing is minimal compared to PCR, NGS, or fluorescence-based protein arrays, and results are obtained in minutes rather than hours or days. Rapid signal readout of the bound signal is detected within minutes (e.g., within minutes, in some cases within 10 minutes).

[0066] 8 is a perspective view of an example system consistent with aspects of the above description according to the present disclosure. As shown and described, the system may include a light source (e.g., laser or LED) that illuminates (e.g., from below) the multiplexed metasurface sensor, the sensor functionalized to attach separate receptor or probe molecules to individual metasurface biosensor pixels, and a CCD detector that captures the light for optical readout after being manipulated (e.g., transmitted light or reflected transmitted light) in response to the functionalized sensor shown in blow-up of exemplary probes 1, 2, and 3.

[0067] By way of example, it is recognized and understood that the above characteristic figures and descriptions are provided to help explain certain aspects (and in some cases advantages) that may be used in the manufacture of such structures and devices, including the exemplary structures and devices described in connection with each figure, as well as other devices, each such described embodiment having one or more related aspects that may be tailored and / or combined with other such devices and examples, as also found in U.S. Pat. No. 1,139,1866 and PCT patent application WO2022076832, described herein and also in the appendix to the provisional application (each of which is incorporated by reference for overlapping subject matter in terms of design concepts such as material types, dimensions and operation of optical elements, discussion of GMR and high Q responses, and ranges characterizing certain high Q GMRs).

[0068] Also, those skilled in the art will recognize various terms used in this disclosure by their ordinary meaning. By way of example, the present specification may describe and / or illustrate aspects useful for implementing the embodiments with various electronic devices, optical elements, material layers, circuits, etc., which may be illustrated as or using terms such as layers, blocks, modules, devices, systems, units, controllers, and / or other circuit type diagrams. Such materials may include semiconductors and / or semiconductor materials, and optical elements, circuit elements, and / or associated circuits may be used along with other elements to illustrate how a particular embodiment may be implemented in any form or structure, step, function, operation, activity, etc. It is also understood that terms illustrating placement, such as top / bottom, left / right, top / bottom, above / below, etc., may be used herein to refer to the relative positions of elements as shown in the figures. It is understood that the terms are used for convenience of notation only, and that in actual use, the disclosed structures may be oriented differently than those shown in the figures. Thus, the terms should not be interpreted as limiting.

[0069] Based on the above description and illustrations, it is apparent to those skilled in the art that various modifications and changes can be made to the various embodiments without strictly following the exemplary embodiments and applications shown and described herein. For example, the method as illustrated in the figures may include steps performed in different orders or may include fewer or more steps while retaining one or more aspects of the embodiments herein. Such modifications do not depart from the true spirit and scope of the various aspects of the present disclosure, including those aspects defined in the claims.

Claims

1. a guided mode resonant metasurface biosensor pixel ("GMR pixel") having a cavity portion that supports a GMR with a specific Q and optics on either side of the GMR pixel to confine light and mitigate energy loss due to light scattering in response to light directed at the GMR pixel of a metasurface sensor; Device.

2. the surface of said GMR pixel is functionalized for attachment of a distinct set of one or more respective receptor and / or probe molecules; in response to light directed at a sample and the functionalized GMR pixel, the functionalized GMR pixel selectively attaches to a distinct type of molecular structure of a biological sample among a plurality of other types of molecular structures; 2. The apparatus of claim 1.

3. The cavity portion has a plurality of nanoblocks, the block of GMR pixels is responsive to light directed at a surface of the GMR pixel, causing the formation of a photonic band gap; Photonic modes with frequencies within the bandgap are not allowed to propagate, and frequencies corresponding to the edges of the bandgap are tuned based on the dimensions of the nanoblocks.

2. The apparatus of claim 1.

4. The device of claim 1 , wherein the optical system includes a first set of one or more nanoblocks and a second set of one or more nanoblocks on opposite sides of the GMR pixel and the cavity portion.

5. the GMR pixel is one of a plurality of similarly constructed GMR pixels, each having a cavity portion that supports GMR at a particular Q and having optics on either side of the GMR pixel to confine light and optimally mitigate energy loss due to light scattering in response to light directed at the GMR pixel of the metasurface sensor; and logic circuitry for selectively accessing different ones of the plurality of similarly constructed GMR pixels to determine a responsivity.

2. The apparatus of claim 1.

6. one surface of said similarly constructed GMR pixels is functionalized for attachment of a distinct set of one or more respective receptor and / or probe molecules; Another surface of the similarly constructed GMR pixel is functionalized for attachment of a different, distinct set of one or more receptor and / or probe molecules; each of said surfaces being collectively functionalized to distinguish different types of biological molecules in a biological sample; 2. The apparatus of claim 1.

7. The apparatus of claim 1 , wherein the optical system functions or acts as a photonic mirror by including a resonant mode.

8. The apparatus of claim 7 , wherein the cavity portion has a plurality of nanoblocks of different dimensions, one said different dimension being distinguishable from another said different dimension by the length of the nanoblock.

9. Directing light onto a guided mode resonant metasurface sensor pixel ("GMR pixel") of a metasurface sensor, the GMR pixel having a GMR-supporting cavity portion with a specific Q; confine light and mitigate energy loss due to scattering of light in response to light directed at the GMR pixel via optics on either side of the GMR pixel; A method for providing the above.

10. The method of claim 9 , wherein the cavity portion has a plurality of nanoblocks that support GMR with a specific high Q of greater than 1000.

11. The method of claim 9 , wherein the cavity portion supports GMR with a specific high Q greater than 10.

12. The method of claim 9 , wherein the cavity portion has a plurality of nanoblocks of different lengths dimensioned such that ends of the plurality of nanoblocks collectively align to form at least a partial tapered dimension between ends of an optical system.

13. A functionalized metasurface sensor including an array of guided mode resonant metasurface biosensor pixels ("GMR pixels"), each of which has a cavity portion supporting GMR with a specific Q and is functionalized for attachment of a distinct receptor or probe molecule; an optical system coupled to opposite ends of each of the GMR pixels and responsive to light directed at the GMR pixels to confine the light and optimally mitigate energy loss due to scattering of the light; a light-responsive data processing circuit responsive to the directed light manipulated by the biological sample at each of the distinct receptor or probe molecules to distinguish between different types of biological molecules in the biological sample; An apparatus comprising:

14. 14. The apparatus of claim 13, wherein at least one of the GMR pixels comprises a material that can be energized by the directed light and has a length corresponding to an illumination wavelength energy that is less than a band gap of the material.

15. 14. The device of claim 13, wherein at least one of the GMR pixels has a cavity portion that supports GMR with a specific high Q of over several thousand.

16. the optical system acts as a photonic mirror; The different types of biological molecules may refer to or include one or more of nucleic acids, proteins, pathogens, and small molecules; 14. The apparatus of claim 13.

17. 14. The device of claim 13, wherein the functionalized metasurface sensor, the optical system, and the light-responsive data processing circuitry are cooperatively configured to detect multiple distinct DNA and RNA sequences, along with different proteins, from a single sample, on a single chip, without relying on recognition of any fluorescent or optical tags.

18. 14. The device of claim 13, further comprising separate receptor or probe molecules for attachment to each of the metasurface biosensor pixels.

19. The device of claim 13 , wherein each of the metasurface biosensor pixels is bioprinted.

20. the functionalized metasurface, the optical system, and the light-responsive data processing circuitry are cooperatively configured to provide a nanophotonics waveguide device; Each of the GMR pixels acts as a waveguide that re-emits a certain amount of the light in the form of radiation losses, the optical system reduces a quality factor associated with photons scattered from the at least one of the GMR pixels.

14. The apparatus of claim 13.

21. functionalizing a metasurface sensor comprising an array of guided mode resonant metasurface biosensor pixels ("GMR pixels") by attaching each of the GMR pixels to a distinct receptor or probe molecule; Each of the GMR pixels includes an optical system fixed to each end of the GMR pixel, the optical system including a cavity portion that supports GMR with a specific Q, and directs light to the metasurface sensor, confines the light, and mitigates energy loss due to light scattering; using a circuit to respond to the directed light manipulated onto a biological sample at each of the GMR pixels and to distinguish between different types of biological molecules in the biological sample; A method for providing the above.

22. 22. The method of claim 21, further comprising distinguishing between different types of biological molecules in the biological sample without relying on recognition of any fluorescent or optical tags.

23. and directing light to the metasurface sensor using a circuit. the circuitry includes a CCD and logic circuitry for responding to the directed light; 22. The method of claim 21.

24. 22. The method of claim 21, wherein the separate receptor or probe molecules for each one of the GMR pixels are patterned through acoustic droplet ejection.

25. 22. The method of claim 21, further comprising customizing or matching the surface functionalization resolution of each of the GMR pixels to detect distinct biomarkers for adjacent ones of the GMR pixels or specific distinct target species of a sample for analysis.

26. 22. The method of claim 21, wherein the separate receptor or probe molecules are attached to the surface of the GMR pixel by applying a material that minimizes non-specific adsorption for binding with an antibody of interest.

27. The GMR pixels are functionalized on a single chip to provide molecular binding to two or more classes of biomarkers selected from one or more of nucleic acids, proteins, and specific substances indicative of disease, infection, and environmental exposure; The discrimination is based on molecular binding detected through a change in scattered light intensity from each of the GMR pixels.

22. The method of claim 21.

28. 22. The method of claim 21, wherein the discrimination is based on the appearance of a sharp scattering spectrum in response to the directed light that changes sensitively upon binding of a biomarker of interest to one or more surfaces of the GMR pixel.

Images