A TWO-TERMINAL DEVICE FOR SENSING A BIOMARKER TO DETECT A DISEASE

Abstract

Ammonia (NH3) emissions are a growing problem worldwide due to their toxicity and reactivity. Exposure to NH3 has serious consequences for human health. Inhalation, ingestion or direct exposure to NH3 causes many side effects such as inflammation, tissue damage and many other scars, as it reacts with water to form ammonium ions. The present invention relates to A two-terminal device for sensing a biomarker to detect a disease, wherein said device comprising Poly-(3,4-ethylenedioxythiophene) (PEDOT), Poly(styrenesulfonate) (PSS), Polyhydroxyl Derivative (PHD), wherein said Polyhydroxyl Derivative (PHD) is coated on the PEDOT:PSS. Due to its pungent odour, NH3 is detectable in the range of 5-53 ppm and causes extreme irritation at concentrations above 80 ppm. We have introduced a UV-based two-electrode ammonia detection system that is stable at room temperature. In its current state, ammonia can be detected in gaseous form. In the absence of ultraviolet radiation, traces of current can be observed in the controlled system. In presence of the UV radiation, the magnitude of the current changes. The presence of ammonia causes a change in amperage. Such a current reading is still observed in the presence of UV radiation.

Specification

Description:FIELD OF THE INVENTION
The present invention generally relates to the field of biosensor. The invention particularly relates to a two-terminal device for sensing a biomarker to detect a disease, wherein said device comprising Poly-(3,4-ethylenedioxythiophene) (PEDOT), Poly(styrenesulfonate) (PSS), Polyhydroxyl Derivative (PHD), wherein said Polyhydroxyl Derivative (PHD) is coated on the PEDOT:PSS. The biomarker is an ammonia.The PEDOT:PSS is exposed with Ultra-violet rays.

PRIOR ART AND BACKGROUND OF THE INVENTION
Liver Cancer disease has tripled over the years and is one of the most dangerous diseases because its symptoms are only seen at later stages, and early detection is difficult. Hepatocellular carcinoma (HCC) is highly malignant and is usually diagnosed at an advanced stage, accounting for more than 80% of primary liver cancers. Detecting HCC at an early stage is not easy, although enormous efforts have been made to find new biomarkers. Many studies have been devoted to finding serum biomarkers for the diagnosis of HCC from the perspective of metabolites. The role of ammonia in cancer cells has yet to be determined. At physiological pH, ammonia exists as ammonium ions (NH4+). Ammonia is mainly removed in the form of urea formed in the liver. Therefore, the concentration of ammonia in the blood must remain very low, because even a slightly elevated concentration (Hyperammonemia) is toxic to the central nervous system (CNS).
A number of different types of devices and methods for detecting cancer cells are available in prior art. For example, the following patents are provided for their supportive teachings and are all incorporated by references. Early diagnosis and a better understanding of the molecular mechanisms leading to HCC occurrence and progression may be considered urgent clinical research. Detection of HCC at the early stage is not easy work despite tremendous efforts that have been made to discover new biomarkers. W. Wang, C. Wei, Genes Dis., 2020, 7(3), 308-319; S. Schlosser, D. Tümen, B. Volz, K. Neumeyer, N. Egler, C. Kunst, H. C. Tews, S. Schmid, A. Kandulski, M. Müller, K. Gülow, Front Oncol., 2022, 12, 1016952; J. Chen, C. Niu, N. Yang, C. Liu, S.-S. Zou, S. Zhu, Pharmacological Research, 2023, 189, 106674.
However, their sensitivity and/or specificity are not satisfactory. Metabolic reprogramming is a recognized hallmark of cancer. It has been known that certain metabolites, such as lactate and amino acid, and their changes in serum may reflect metabolic changes in tumour tissue. S. D. Matteis, A. Ragusa, G. Marisi, S. D. Domenico, A. C. Gardini, M. Bonafè, A. M. Giudetti, Oxidative Medicine and Cellular Longevity, 2018, 7512159, 13; N. Fujiwara, S. L. Friedman, N. Goossens, Y. Hoshida, J Hepatol., 2018, 68(3), 526-549.
Many studies were devoted to discovering serum biomarkers of HCC diagnosis from the aspect of metabolites. Ping Luo et al defined a group of biomarkers of serum metabolites, including phenylalanyl-tryptophan and glycine chelate. S. D. Matteis, A. Ragusa, G. Marisi, S. D. Domenico, A. C. Gardini, M. Bonafè, A. M. Giudetti, Oxidative Medicine and Cellular Longevity, 2018, 7512159, 13; N. Fujiwara, S. L. Friedman, N. Goossens, Y. Hoshida, J Hepatol., 2018, 68(3), 526-549.
These studies may reflect various metabolic aspects of HCC. Still, lack of sufficient validation restricts further clinical applications of these biomarkers, because most laboratories cannot access mass spectrometers for easily detecting metabolites. Together with another amino acid metabolism, they lead to the accumulation of ammonia in the tumour microenvironment. Hence ammonia metabolism plays different roles in cancers.
Most researchers believe ammonia is a toxic cellular by-product of glutamine metabolism and needs to be metabolized into a non-toxic form, such as urea, to be excluded from the body. S. A. Khan, S. Tavolari, G. Brandi, Liver Int., 2019, 39, 19- 31;X. Li, H. Zhu, W. Sun, X. Yang, Q. Nie, X. Fang, Cancer Cell Int., 2021, 9, 21(1), 479. But Jessica B et al prove that breast cancer cells can recycle glutamine amide for biosynthesis. J. Spinelli, H. Yoon, A. Ringel, S. Jeanfavre, C. Clish, and M. Haigis, Science, 2017, 358, 941-946. Therefore, the role of ammonia in cancer cells remains to be determined. The liver represents a perfect metabolic model that governs body energy metabolism through different metabolites' physiological regulation, including sugars, lipids, amino acids, and the urea cycle.
The prior art reference, CN102636525A discloses a gas sensor chip (P) and a measuring system (Q) of the gas sensor chip (P) as well as a manufacturing method of the gas sensor chip (P). The gas sensor chip (P) is a sensor which is used for preliminarily determining the freshness in the field of food, medicine and the like. The gas sensor chip (P) comprises a flexible substrate (1), flexible electrode pairs (2) arranged on the flexible substrate (1) and a sensing layer (3), wherein the sensing layer (3) is arranged between the flexible electrode pairs (2). In order to better apply the gas sensor chip (P) provided by the invention, the invention provides the measuring system (Q) comprising the gas sensor chip (P), a voltage source (9), an alarm circuit (8), an ampere meter (10) and a measuring electrode pair (11), wherein the voltage source (9), the alarm circuit (8), the ampere meter (10) and the measuring electrode pair (11) are connected in a measuring circuit in series, and the measuring electrode pair (11) is connected with the flexible electrode pairs (2) on the gas sensor chip (P). The manufacturing method provided by the invention greatly enhances the production efficiency of the gas sensor chip (P) and enlarges the application scope.
Another prior art document, JP6654433B2 discloses a process for producing a capacitor, a capacitor obtained by this process, an electronic circuit, the use of a capacitor, a process for producing a dispersion, a dispersion obtained by this process, for producing an organic solar cell. The organic solar cells obtained by this process and the use of dispersions for producing organic solar cells. A process for producing a solid electrolyte in a capacitor, comprising a dispersion comprising already polymerized thiophene and a polyanion as counterion, such as a PEDOT / PSS dispersion known from the prior art Is applied to the oxide layer and the dispersant is then removed by evaporation, processes are also known from the prior art.
Yet another prior art document, CN106770515B discloses a kind of organic electrochemistry transistor sensor based on molecular engram film, it is characterized by: the gold electrode that the grid of organic electrochemistry transistor sensor is film modified using molecular engram, it is polymerize as template molecule, with corresponding function monomer by cyclic voltammetry using object to be detected, polymer film first is formed in gold electrode surfaces, then the template molecule elution in polymer film is fallen and is obtained；Grid regulates and controls the channel current between source electrode, drain electrode by the solution of object to be detected, constitutes the organic electrochemistry transistor sensor for being used for Selective recognition object to be detected. The present invention combines molecular imprinting technology with organic electrochemistry transistor device, utilize the specific selection of molecular imprinting technology and the signal amplifying function of organic electrochemistry transistor sensor, it treats detectable substance and carries out specific recognition, selective absorption can be carried out to micro or even trace object to be detected, selective good, high sensitivity, detection limit are low.
Yet another prior art document, US9291613B2 discloses Sensors and detection systems suitable for measuring analytes, such as biomolecule, organic and inorganic species, including environmentally and medically relevant volatiles and gases, such as NO, NO2, CO2, NH3, H2, CO and the like, are provided. Certain embodiments of nanostructured sensor systems are configured for measurement of medically important gases in breath. Applications include the measurement of endogenous nitric oxide (NO) in breath, such as for the monitoring or diagnosis of asthma and other pulmonary conditions.

However, above mentioned references and many other similar references has one or more of the following shortcomings: (a) not discloses a detection of ammonia release from live cells; (b) do not disclose role of porous polyhydroxyl derivative; (c) mostly discloses solid electrolytes and its application; (d)not obtaining higher efficiency; (e) not use of polymeric materials; (f) complex structures; and (g) expensive.
The present application addresses the above mentioned concerns and short comings with regard to providing a novel and improved a two-terminal device for sensing a biomarker to detect a disease.
SUMMARY OF THE INVENTION
In the view of the foregoing disadvantages inherent in the known devices and methods for detecting cancer cells now present in the prior art, the present invention provides a two-terminal device for sensing a biomarker to detect a disease. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide new, simple and cost-effective a two-terminal device for sensing a biomarker to detect a disease which has all the advantages of the prior art and none of the disadvantages.
The main objective of the present invention is to provide a two-terminal device for sensing a biomarker to detect a disease, wherein said device comprising Poly-(3,4-ethylenedioxythiophene) (PEDOT), Poly(styrenesulfonate) (PSS), Polyhydroxyl Derivative (PHD), wherein said Polyhydroxyl Derivative (PHD) is coated on the PEDOT:PSS..
Another objective of the present invention is to provide the two-terminal device for sensing a biomarker to detect a disease, wherein said biomarker is Ammonia.
Yet another objective of the present invention is to provide the two-terminal device for sensing a biomarker to detect a disease, wherein said PEDOT:PSS is exposed with Ultra-violet rays.
Yet another objective of the present invention is to provide the two-terminal device for sensing a biomarker to detect a disease, wherein said biomarker is detectable in the range of 5-53 ppm.
Yet another objective of the present invention is to provide the two-terminal device for sensing a biomarker to detect a disease, wherein said disease is infectious and terminal diseases affecting the liver, kidney, and lungs directly/indirectly like Hepatitis, Liver cirrhosis, Renal dysfunction, Chronic Kidney Disease (CKD), Peptic Ulcers COVID-19 (SARS -CoV - 2), Peptic ulcers commonly caused by Helicobacter pylori (H. Pylori) infections.
Yet another objective of the present invention is to provide the two-terminal device for sensing a biomarker to detect a disease,
Yet another objective of the present invention is to provide the two-terminal device for sensing a biomarker to detect a disease, wherein said device is operable at biologically relevant lower voltages (</= 1 V).
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practised and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is achieved to the following detailed description thereof. Such description refers to the annexed drawings wherein:
Fig. 1 depicts Graphical Representation of Photo-electronic Detection of gaseous ammonia by a device in accordance with the present invention.
Fig.2 depicts electrical characteristics graphs of a device, (a) Current Output without and with UV. (b) Current Output under UV after ammonia exposure., in accordance with the present invention.
Fig. 3 depicts experimental Setup under UV off and illumination in accordance with the present invention.
Fig. 4 depicts sensor response to ammonia: (a) Current Output with different ammonia concentrations. (b) Current Output under dark after ammonia exposure showing reusability of device .in accordance with the present invention.
Fig. 5 depicts Current Output of a device with different analytes under dark.in accordance with the present invention.
Fig. 6 depicts Photoluminescence Characteristics of PHD layer upon exposure to ammonia in accordance with the present invention.
Fig. 7 depicts Sensor Characteristics upon exposure to ammonia in accordance with the present invention.
Fig. 8 depicts Time-Resolved Photo-luminescence (TRPL) study of PHD upon ammonia exposure in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural and logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents. The present invention is described in brief with reference to the accompanying drawings. Now, refer in more detail to the exemplary drawings for the purposes of illustrating non-limiting embodiments of the present invention.As used herein, the term "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers or elements but does not exclude the inclusion of one or more further integers or elements.As used herein, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a device" encompasses a single device as well as two or more devices, and the like.
As used herein, the terms "for example", "like", "such as", or "including" are meant to introduce examples that further clarify more general subject matter. Unless otherwise specified, these examples are provided only as an aid for understanding the applications illustrated in the present disclosure, and are not meant to be limiting in any fashion. As used herein, the terms "may", "can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic. Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
Thus, for example, it will be appreciated by those of ordinary skill in the art that the diagrams, schematics, illustrations, and the like represent conceptual views or processes illustrating systems and methods embodying this invention.
Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
Exposure to NH3 has serious consequences for human health. Inhalation, ingestion or direct contact with NH3 causes many side effects such as inflammation, tissue damage and many other scars due to its reaction with water and the formation of ammonium ions. R. P. Padappayil & J.Borger, Ammonia toxicity, 2021, StatPearls [Internet]. Due to its pungent smell, NH3 is detectable between 5-53 ppm and causes extreme irritation above 80 ppm concentration. In Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 6. 2008, National Academies Press (US). Extensive research has led to the development of several ammonia detection systems. They are based on (but not limited to) colourimetric or fluorometric methods, gas or liquidchromatography-based methods, and electrochemical or enzyme-based methods. However, each method has advantages or disadvantages in terms of sensitivity, selectivity, ease of preparation, production costs, efficiency and stability compared directly to the others. T. N. Annisa, S. H. Jung, M. Gupta, J. Y. Bae, J. M. Park, & H. I. Lee, ACS applied materials & interfaces, 2020, 12(9), 11055-11062.
One example of an ammonia detection system is the use of silver nanoparticles. UV exposure to silver nitrate solution enables the synthesis of silver nanoparticles. The colourimetric change mediated by these silver nanoparticles results in the detection of ammonia in solution in the range of 1-100 ppm. Thus, the availability of such detection methods makes it possible to measure ammonia in solutions such as water. However, the manufacturing and synthesis of such silver nanoparticle-based ammonia sensors are not environmentally friendly and pose a threat tothe ecosystem. T. Ritthichai & V. Pimpan, Journal of King Saud University-Science, 2019,31(2), 277-284; S. T. Dubas & V. Pimpan, Talanta, 2008, 76(1), 29-33; E. Detsri, J. Popanyasak,N. Laomaneenopparat, & K. Warngbun, In Advanced Materials Research, 2015, 1105, 225-230.Therefore, there is an urgent need to design less hazardous and more sensitive ammonia sensors.
In the present invention it is established that a UV-based two-electrode ammonia detection system that is stable at room temperature. In the current state, ammonia can be detected in its gaseous form.
The current trace is detectable in the controlled system in the absence of ultraviolet radiation. The amplitude of the current has changed in the presence of UV light. The existence of ammonia induces a shift in current intensity. Such current readout is further noticed in the presence of UV. This enables sensitive detection of ammonia. Therefore, we report a UV-based design of an ammonia sensor that is sensitive, scalable, cost-effective, reusable and eco-friendly.
The present invention relates to a two-terminal device for sensing a biomarker to detect a disease, wherein said device comprising Poly-(3,4-ethylenedioxythiophene) (PEDOT), Poly(styrenesulfonate) (PSS), Polyhydroxyl Derivative (PHD), wherein said Polyhydroxyl Derivative (PHD) is coated on the PEDOT:PSS.. The biomarker is Ammonia. Further, PEDOT:PSS is exposed with Ultra-violet rays. The biomarker is detectable in the range of 5-53 ppm. The disease is infectious and terminal diseases affecting the liver, kidney, and lungs directly/indirectly like Hepatitis, Liver cirrhosis, Renal dysfunction, Chronic Kidney Disease (CKD), Peptic Ulcers COVID-19 (SARS -CoV - 2), Peptic ulcers commonly caused by Helicobacter pylori (H. Pylori) infections. The device is operable at biologically relevant lower voltages (</= 1 V). Another objective of the present invention is the bi-layer PHD-based approach presents a highly selective both with/without UV-based detection of protein biomarkers with low concentrations in physiological environments. In further objective of the present invention is to provide at wo-terminal PHD-based biosensor wherein it selectively detects the presence of ammonia in gaseous form with/without UV over other interfering analytes. In another objective of the present invention ammonia is introduced as a biomarker to form Point-of-Care (PoC) for effective early diagnosis with/without UV for abnormal liver, kidney, and lung functioning in clinical/environmental applications. In another objective, the present invention provides two-terminal PHD-based sensing for the selective on-site recognition of ammonia in gaseous form both with/without UV at room temperature.
Direct exposure to NH3 poses a serious health risk due to multi-organ dysfunction (liver, kidney, lungs). Therefore, long-term exposure to high concentrations of ammonia in the human body is usually related to the development of fatal diseases such as chronic kidney disease (CKD), pepticulcer and even epidemic diseases and COVID-19 (SARS-CoV-2) due to weakened immune response. Ammonia is normally formed in muscle and peripheral tissues and transported to the liver to be converted to urea by the urea cycle. The most important signal of acute and chronic liver damage is elevated ammonia, a life-threatening metabolic condition. There is still a need to develop a non-invasive, real-time, accurate and rapid screening device to detect ammonia levels for better monitoring of such diseases. In this context, low ammonia concentration, location and abundance of disturbances/interferences are considered to be the main challenges in monitoring certain diseases. A two-terminal PHD-based device demonstrates accurate and selective detection of ammonia. The detection data and results obtained with the two-terminal device were found to be highly selective for the detection of ammonia over other analytes and interfering substances, making it very useful in clinical applications.
In the present invention, a two-terminal device with a polyhydroxyl derivative has been developed and ammonia sensing has been achieved under a UV on/off state.
the device has excellent current characteristics and can be operated with voltages as low as 1V or less. The poly-hydroxyl film is optimal at room temperature due to its crosslinked homogenous texture. The device is highly sensitive and selective towards ammonia both under UV on/off state.
PL and TRPL analysis of the sensing layer of the device showcases the photoluminescence with high intensity (brightness) and prolonged stability.
The reusability study of the device proved another important aspect of our device. Thus, new possibilities and findings could be further explored using such materials in different configurations.
A two-terminal device was fabricated with a poly-hydroxyl derivative used for coating. The electronic transfer characteristic indicated at UV on/off is shown in Figure 1. The measurements were done inside a black box under UV on state subsequently changes the channel conductance and current decreases (Figure 2). Again, after exposure to ammonia the current further shifts. This system is found to be highly sensitive towards ammonia, i.e., it forms an ammonia-sensitive layer. Hence, the presence of a small concentration of ammonia is selectively detected. It is found that the electron transfer curve shifts significantly upon the addition of different concentrations of ammonia. Various analytes, such as diethylamine, propylamine, ethanolamine, triethylamine, pyridine and cyclo hexylamine have been tested with this device system. Two terminal sensing device is based on a base layer of PEDOT: PSS polymer with a polyacrylate layer on top of it. In normal ambient conditions of 298K and 1 bar pressure, the I-VCharacteristics of the two-terminal device are shown in Figure 2.
On further analysis, it is evident that there is a reduction in current values when the device is
exposed to NH3(g). The reduction in current is due to the elevation in resistance values of the
device due to ionic interactions between NH3(g) with polyhydroxyl (PHD) layer based on dipolarinteractions between polar ammonia gas and polar carboxy part (-COO-) of polyhydroxyl layerof the sensor.When ammonia gas NH3(g) interacts with the PHD layer it is absorbed due to many ionicinteractions mainly in terms of H- bonds formed between the polycarboxy (-COO-) part of PHDand ammonia vapours. This absorbtion of ammonia molecules leads to depletion in electrondensity at PEDOT: PSS showing p-type material properties. Further, current values are seen withincreasing ambient concentration of ammonia vapours (NH3(g)) which indicates the increasingabsorbtion of ammonia vapours on the sensing PHD layer and in turn making the PEDOT: PSSLayer (Fig. 4a). The reusability of the device has been explored as seen in figure 4b. As seen inFigure 4b, upon exposure to ammonia and removal of ammonia the current values increase anddrop respectively. We can deduce that sensor current varies inversely with increasing ambient ammonia vapour concentration; which signifies the p-type semiconducting behaviour of the sensor. This property is further analysed with other reducing analytes like diethylamine, propylamine, ethanolamine, triethylamine, pyridine and cyclohexylamine (Figure 5). Results obtained indicate that the sensor behaves as a p-type semiconducting material in the presence of almost all reducing analytes and the maximum selectivity of the sensor for ammonia vapours isseen. The device is highly sensitive and selective towards NH3(g) vapours can be explained based on the maximum interaction of NH3(g) with the PHD layer. Among all the gaseous analytes, NH3(g)has maximum potential for H-bonds which is around 6 H-bonds per molecule of ammonia. In all other cases, the association between vapours and PHD is somewhat weaker due to fewer H-bonds formed per molecule, making the device most selective for ammonia detection. Furthermore, the gas sensing capability of our device is purely based upon the interaction of absorbed gas with the PEDOT: PSS base layer making it a p-type semiconducting material. These interaction changes the resistance or conductance profile of the conduction band which is evident in variation in the I-V characteristic of the device.
EFFECT OF UV RADIATION
Ultra-violet radiations are highly energetic which leads to homolytic bond cleavage of covalent bonds present in organic molecules of the sensing layer producing various free radicals in the process. Irradiation of UV rays makes the sensing surface more oxidising due to a high number of free radicals generated in homolytic bond cleavage which in turn increases the absorbtion of reducing analytes over it. Due to the more concentrated absorbtion of gas over the PHD sensing layer, a further decrease in current is seen in the I-V characteristic of the sensor. It is evident that the device is highly sensitive and selective towards NH3(g).
In Photo-luminescence (PL) analysis of the sensing layer, it is evident that the sensing layer is
highly florescent with high intensity of photons obtained at lower wavelengths as shown in Figure 6. The higher intensity is fairly visible in terms of very bright light obtained during PL
analysis. High intensity vs wavelength ratio iterates a high photo-sensitivity and photo luminescence sensing layer of the device. The intensity of photo-luminescence decreases when the sensing layer is exposed to gaseous analytes due to increasing absorbtion of gaseous analytes over the sensing layer.
Under excitation, the electron density increases in this region. After the addition of ammonia, it attaches to the (-C=O) region and accumulates by drawing all the electron density towards this region (Figure 7). Therefore, more electrostatic potential is observed in this region rather than in other regions.
In Time-Resolved Photo-luminescence (TRPL) analysis of the sensing layer, the plots between the number of photons emitted with time elapsed are obtained. The sensing layer exhibits stable photo-luminescence with a decay half-life period (t1/2) of 2.5ns. Furthermore, the photoluminescence half-life time (t1/2) further increases when the sensing layer is exposed to different gaseous analytes indicating the improving stability of the sensor layer. TRPL variation of raw sensor and sensor exposed to NH3(g) is obtained as in Figure 8.
MATERIALS AND METHODS
PEDOT: PSS, Acrylic acid and 30% Ammonia solution were purchased from Sigma-Aldrich. Glycerol was purchased from Merck and p-toluene sulfonic acid from Loba Chemie. CV measurements were carried out using a CH instruments Model 700D series. Ag/AgCl was used as the reference electrode and 0.1M NaCl as an aqueous electrolytic solution. The thickness of the deposited films was optimized using a profilometer (Dektat-150).

EXAMPLE 1:
SENSOR DESIGN AND CONSTRUCTION
Microscopic Glass slides of dimensions 1cm X 2 cm cleaned in Piranha solution for 1 hour and washed several times with deionised water were utilized as substrates. The cleaned substrates were then dried; ionized and subsequently 100 nm thickness aluminium contacts were thermally deposited on them inside the Glove Box. A channel of dimensions 30 mm length (L) and 2 mm width (W) was obtained which was used as the Source (S) and Drain (D). 30 nm thick PEDOT:PSS films were coated on these aluminium deposited substrates. The coated substrates were again heated at 130 °C for 1 hour. The synthesized poly-hydroxyl layer was coated over the PEDOT: PSS region and heated at 50 °C for 30 minutes.

EXAMPLE 2:
ELECTRICAL CHARACTERIZATION AND MEASUREMENTS
All the electrical characterizations of the devices were carried out under ambient conditions at room temperature using a Keithley2614B. A positive Gate bias (Vg) was applied with an Ag/AgCl electrode, and the two aluminium electrodes served as a source (S) and drain (D). The ammonia sensing experiments were performed at Drain voltage Vd = -0.2 V with a Gate voltage Vg sweep ranging from 0 to 0.9V in 5ml electrolyte solution at a pH of 7. The analyte and ammonia solutions were confined in a 10 mL beaker and mixed with electrolyte before testing.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-discussed embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description.
The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the embodiments.
While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention.
, Claims:We Claim:

1. A two-terminal device for sensing a biomarker to detect a disease, wherein said device comprising Poly-(3,4-ethylenedioxythiophene) (PEDOT), Poly(styrenesulfonate) (PSS), Polyhydroxyl Derivative (PHD), wherein said Polyhydroxyl Derivative (PHD) is coated on the PEDOT:PSS.

2. The two-terminal device for sensing a biomarker to detect a disease as claimed in claim 1, wherein said biomarker is Ammonia.

3. The two-terminal device for sensing a biomarker to detect a disease as claimed in claim 1, wherein said PEDOT:PSS is exposed with Ultra-violet rays.
4. The two-terminal device for sensing a biomarker to detect a disease as claimed in claim 1, wherein said biomarker is detectable in the range of 5-53 ppm.

5. The two-terminal device for sensing a biomarker to detect a disease as claimed in claim 1, wherein said disease is infectious and terminal diseases affecting the liver, kidney, and lungs directly/indirectly like Hepatitis, Liver cirrhosis, Renal dysfunction, Chronic Kidney Disease (CKD), Peptic Ulcers COVID-19 (SARS -CoV - 2), Peptic ulcers commonly caused by Helicobacter pylori (H. Pylori) infections.

6. The two-terminal device for sensing a biomarker detecting a disease as claimed in claim 1, wherein said device is operable at biologically relevant lower voltages (</= 1 V).

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