"A MALARIA DETECTION SENSOR BASED DEVICE USING NANOCOMPOSITE LAYERS OF MATERIAL"

Abstract

The present invention relates to a biosensor device using metal/defect/metal multilayer nanocomposite photonic crystal is proposed for malaria diagnosis. The defect layer corresponds to different hemoglobin concentration related to malarial stages. Transfer matrix method is used to estimate transmission, reflection and absorption properties of the sensor. To analyse the tunable characteristics, metal layer width, incident angle and defect layer, refractive index has been varied. It is found that defect modes shifting improved further with increase in metal layer thickness and incident angle. The proposed sensor has been found to be of higher sensitivity as 1210 nm/RIU for malaria diagnosis as compared to our earlier works.

Specification

Description:Field of the Invention
[0001] The present invention relates to a sensor-based device using nanocomposite layers of material.
Background
[0002] The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Generally, Photonic crystals (PCs) have recently attracted a lot of attention due to the control over photon propagation in crystal due to the periodic arrangement of the dielectric. The periodic arrangement of dielectric give rise to photonic bandgap (PBG) similar to the periodic arrangement of atoms gives rise to electronic bandgap in semiconductor to control the propagation.
[0004] Recently, One-dimensional PC (1-D PC) is the simplest structure that shows periodicity along a single direction. Recently, 1-D PC has been studied with tunable properties for various potential applications such as optical filter, mirrors, switches, Wavelength division multiplexer, sensors etc.
[0005] The break in periodicity of the ordered PC causes a localized defect mode in PBG. Such localized defect modes have strong dependence on the defect layer's parameters such as refractive index and width. The localized mode can also be tuned by changing the prefabricated defect layer's parameters. In addition, the tuning properties can be done using externally controlled parameter like temperature, pressure, electric field and magnetic field etc. The tunable characteristic of defect mode can be used as a tunable narrow filter, sensor and switching application.
[0006] In the proposed invention we introduced two metal layer on both side of defect layer in a 1-D PC structure to improve sensitivity of device for malaria detection. The defect layer corresponds to the hemoglobin concentration at various stages of malaria. This structure is used to investigate the tunable characteristic with the variation of metal layer width, incident angle and defect layer refractive index.
[0007] On the other hand, there are various techniques & methods to enhance the fluorescence, which are disclosed in patent literature. Few exemplary documents are discussed below.
[0008] The US010048200B2 (by: PHOTONICSYS LTD., Wahat, Alsalam-Neveh Shalom (IL), (USA)) relates to a SPR sensor that comprises a multi-layered plasmonic structure on a substrate for sensing. The SPR sensor has an enhanced figure of merit and lower limit of detection (system noise divided by the sensitivity) by at least two orders of magnitude than prior art SPR sensors. The plasmonic structure of the invention comprises a Nanostructured Porous Metal Layer (NPML) and at least one of: (a) buried dielectric layer under the nano-porous metal layer; (b) a nano-dimensional high index layer on top of the metal layer; and (c) a molecular layer for bio-functionalization adjacent to an analyte layer. The invention also encompasses many embodiments of measuring systems that comprise the SPR sensors of the invention with improved signal to noise ratio.
[0009] The US8538214B2 (by: Xian Tong Chen et al., (US)) relates to an optical resonator. The optical resonator includes an input optical waveguide and a closed loop coupled to the input optical waveguide. The closed loop is adapted to receive light from the input optical waveguide, wherein the closed loop includes at least one hole formed within a portion of the closed loop.
[00010] To US7922976B2 (by: Achyut Kumar Dutta, Rabi S Sengupta, (US)) relates to a sensing device able to do concurrent real time detection of different kinds of chemical, biomolecule agents, or biological cells and their respective concentrations using optical principles. The sensing system can be produced at a low cost (below $1.00) and in a small size (˜1 cm3). The novel sensing system may be of great value to many industries, for example, medical, forensics, and military. The fundamental principles of this novel invention may be implemented in many variations and combinations of techniques.
[00011] The US9366571B2 (by: Nadia Pervez et al. (US)) relates to an optical waveguide coupled to a photonic crystal comprising a dielectric material, the photonic crystal located on an exterior surface of the optical waveguide and comprising a first surface including a first array of periodic features on or within the dielectric material, the array extending in at least two dimensions and including an effective dielectric permittivity different from the surrounding dielectric material. In an example, the periodic features include a specified lattice constant, the periodic features configured to extract a portion of propagating optical energy from the waveguide through the photonic crystal, the portion determined at least in part by the specified lattice constant.
[00012] The 202321082336 (by: DR. JAYAVANT L. GUNJAKAR et al., MAHARASHTRA (India)) relates to a method for chemically converting thin films of ZnO nanosheets into highly orientated thin films of zinc-aluminum layered double hydroxide (Zn-Al-LDH). The structural analysis of chemically converted thin films of zinc oxide nanosheets clearly demonstrated the formation of hexagonal Zn-Al-LDH. The surface morphology of chemically converted thin films reveals the presence of Zn-Al-LDH nanosheets. The Zn-Al-LDH showed remarkable selectivity for NO2 detection, with a maximum NO2 response of 66%, and a fast response time of 3 seconds at room temperature (27 °C).
[00013] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
Objects of the Invention
[00014] The principal object of the present invention is to overcome the disadvantages of the prior art.
[00015] Another object of the present invention is to focuses on an optical biosensor using metal/defect/metal multilayer photonic crystal for malaria diagnosis.
[00016] Another object of the present invention is to obtained the high sensitivity, high quality factor and low optical loss coefficients.
Summary
[00017] The present invention relates to a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention.
[00018] In an aspect, the present invention introduced two metal layers on both side of defect layer in a 1-D PC structure to improve sensitivity of device for malaria detection. The defect layer corresponds to the haemoglobin concentration at various stages of malaria. This invention is used to investigate the tunable characteristic with the variation of metal layer width, incident angle and defect layer refractive index.
[00019] In another aspect, the present invention provides a multilayered 1-D PC structure with defect between two metal layers. The break in periodicity of 1-D PC generates a localized defect mode. Such defect mode show dependence on the defect layer refractive index and width, as the presence of the metal layer develops surface plasmon wave at the interface of metal-dielectric, which affects the position and peak of localized defect mode. Therefore, the proposed structure is used to study the tunable characteristic for sensing application.
[00020] In another aspect, the transmission, reflection and absorption properties of 1-DPC structure is obtained by transfer matrix method (TMM). The material used in present invention is considered as homogeneous, isotropic, and non-magnetic. The electric and magnetic fields can be calculated using continuity conditions at the interface of each layer. Using this method the optical properties like transmittance. Reflection, sensitivity, quality factor etc. have been evaluated.
[00021] Various computer programs, mathematical tools, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which numerals represent like components.
Brief Description of the Drawings
[00022] Fig. 1 illustrates an exemplary block diagram of photonic crystal biosensor having a one-dimensional structure with a thin film of blood sample with two nanocomposite layers of materials.
[00023] Fig. 2 illustrates an exemplary diagram of the transmittance peaks for different stages of malaria.
Detailed Description
[00024] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive blocks, the inventive subject matter is considered to include all possible combinations of the disclosed elements.
[00025] Fig. 1 illustrates an exemplary system containing a photonic crystal biosensor. Here, the refractive index of layer 102 is denoted by n1 and refractive index of layer 103 is denoted by n2. The width of layer 102 is denoted by d1 and width of layer 103 is denoted by d2. The total width of unit cell is defined by d = d1 + d2.
[00026] In an embodiment, the biosensor system 100 includes a thin layer of silicon and SiO2 material 102 and 103 respectively. There are five alternate layers of these materials with a single defect layer of blood sample 104. This defect layer is sandwiched between two thin nanomaterials of Ag 105 and 106 respectively. The input signal 101 is launched into the photonic crystals and output is obtained at the end of device 107.
[00027] In an embodiment, the width of Si and SiO2 layer are taken as quarter wavelength with reference wavelength as ?0 = 900 nm. The quarter-wave stacked 1- D PC has an advantage of wide PBG at the desired reference wavelength. In this work, we are interested in the study of the tunable characteristics with a metal layer. The dielectric constant for metal is complex, whereas the plasma frequency and damping constant of silver is 2.18 PHz and 4.35 THz, respectively.
[00028] In an embodiment, the defect layer's refractive index and width are considered as 1.35 and 500 nm, along with the metal layer's width as 5nm for primary study. The transmission, reflection and absorption for the proposed structure are calculated by TMM.
[00029] In an embodiment, the transmission, reflection and absorption values of the structure is obtained at 46.5 %, 25 %, and 28.5 % respectively at a given wavelength. The transmission corresponds to defect mode due to the defect layer along with metal layers. Here, the metal layer besides the defect layer creates surface plasmon wave (SPW) at metal-dielectric interfaces.
[00030] In another embodiment, the effect of variation of refractive index, we have taken the width of defect layer as 2.5µm. The transmission is plotted with refractive index value varying from 1.35 to 1.45 of defect layer. The transmission peak shifts linearly as the defect layer refractive index changes, due to increase in effective thickness of defect layer. The transmission peak shifting with the defect layer refractive index improve as the incident angle increase in both TE and TM modes.
[00031] In another embodiment, It`s observed that the sensitivity of proposed structure increase with incident angle and obtain a maximum value at an incident angle of 850, while the average value of transmission peak decreased with incident angle. Therefore, the optimum value of sensitivity for the proposed 1-D PC structure is achieved as 1210 nm/RIU with the defect layer width of 7µm along with the metal layer width of 15 nm.
[00032] In an embodiment, the sensitivity is improved more than twice by introducing metal layer and angular variation. Therefore, the geometrical parameters to achieved maximum sensitivity are taken as thickness of defect layer = 7µm, thickness of metal layer = 15 nm, while the transmission is taken at incident angle 850 for TM mode. The transmission peaks for different stages of malaria are plotted as shown in Fig.2.
[00033] In an embodiment, it is clear the transmission values are quite reasonable varying from 33.7% to 69.75%. Therefore, the proposed 1-D PC structure has high sensitivity of about 1210 nm/RIU for malaria diagnosis, which is higher than the previous reported research work.
[00034] In an embodiment, the proposed 1-D PC structure with a narrow filter device application. Since, the refractive index of material is dependent on environmental parameters like temperature, pressure, humidity, etc., therefore, this can be used to construct externally controlled tunable filters or optical switching devices using the proposed 1-D PC structure.
[00035] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
[00036] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprise" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.
, Claims:I/We claim:
1. A sensor device comprises:
a nanocomposite layers of materials, a thin defect layer of blood sample sandwiched between to nano layers of Ag material, a Transfer Matrix Method to evaluate the optical properties like transmittance, reflectivity, sensitivity, quality factor etc., of nanocomposite materials, The defect layer corresponds to different hemoglobin concentration related to malarial stages, metal layer width, incident angle and refractive index to design a sensor.
2. The system of claim 1, wherein a defect layer of blood sample is sandwiched between two nanocomposite layers of Ag materials.
3. The system of claim 1, the defect layer corresponds to different hemoglobin concentration related to various malarial stages.
4. The system of claim 1, wherein Transfer matrix method is used to estimate transmission, reflection and sensitivity.
5. The system of claim 1, wherein a transmission peak is found to decrease with incident angle on TE polarization.
6. The system of claim 1, wherein the proposed sensor has been found to be of higher sensitivity as 1210 nm/RIU for malaria diagnosis.
7. The system of claim 1, wherein the proposed sensor has been performed at an angle of incidence of 850 for malaria diagnosis.
8. The system of claim 1, wherein the transmittance peak has been used to identify the malaria at early stage.
9. The system of claim 1, wherein the sensitivity for the proposed 1-D PC structure is achieved as 1210 nm/RIU with the defect layer width of 7µm along with the metal layer width of 15 nm.

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