A system for the synthesis and production of a nanocomposite of cerium molybdate and graphitic carbon nitride for the detection of uric acid in sweat

Abstract

A system for the synthesis and production of a cermolybdate graphitic carbon nitride (Ce2 (Mo4)3@g-C3N4) nanocomposite for the detection of uric acid in sweat, comprising: a) a cermolybdate synthesis unit for the production of Ce2 (Mo4)3 nanoparticles by hydrothermal treatment, wherein the cermolybdate synthesis unit comprises: • a reaction vessel containing cerium nitrate and ammonium molybdate in a molar ratio of 2:3 in a solvent mixture of ethanol and deionized water, • a surfactant additive system configured to add cetyltrimethylammonium bromide (CTAB) for stabilization, and • a hydrothermal reactor configured to heat the mixture to 180°C for 24 hours; b) a plant for the synthesis of graphitic carbon nitride, configured to produce g-C3N4 by thermal polymerization of melamine under inert atmospheric conditions at temperatures of 400 °C to 600 °C; and c) a nanocomposite formation unit configured to combine Ce2(Mo4)3 and g-C3N4 to form the Ce2(Mo4)3@g-C3N4 nanocomposite, wherein the nanocomposite formation unit comprises: • an ultrasound system configured to disperse the components at the molecular level and allow them to interact with each other, and • a drying system for removing residual solvents.

Description

AREA OF INVENTION

[0001] The present disclosure relates to a system for the synthesis and production of a cermolybdate graphitic carbon nitride (Ce2 (Mo4)3@g-C3N4) nanocomposite for the detection of uric acid in sweat. BACKGROUND OF THE INVENTION

[0002] Uric acid (UA) is an important biomarker for various metabolic and kidney diseases, including hyperuricemia, gout, cardiovascular disease, and chronic kidney disease. Conventional UA assay systems, such as high-performance liquid chromatography (HPLC), enzymatic assays, and spectrophotometric methods, are characterized by high operating costs, labor-intensive sample preparation, limited mobility, and reliance on invasive sampling techniques. These limitations restrict their suitability for continuous or real-time health monitoring.

[0003] Non-invasive electrochemical biosensor systems for determining uric acid in sweat have proven to be promising alternatives. However, existing systems are critically dependent on electrode materials that exhibit high electrocatalytic activity, excellent stability, and selectivity in complex physiological environments.

[0004] Cerolybdate (Ce2(Mo4)3) has attracted interest for electrochemical applications due to its diverse redox chemistry and variable oxidation states. However, pure Ce2(Mo4)3-based systems exhibit two major limitations: (i) an inherently low electronic conductivity, which limits charge transfer efficiency, and (ii) strong agglomeration of the nanoparticles during synthesis, which drastically reduces the available surface area and accessibility of catalytic centers.

[0005] Graphitic carbon nitride (g-C3N4) has gained importance as a conductive support material due to its large surface area, two-dimensional conjugated structure, excellent chemical stability, and semiconducting properties. Systems with g-C3N4 improve electron mobility and provide anchoring sites for the nanoparticle dispersion, thereby reducing aggregation.

[0006] Despite advances in biosensor development, there remains a lack of scalable, cost-effective, and reproducible synthesis systems for hybrid nanocomposites that can be integrated into portable diagnostic devices. Hydrothermal synthesis methods represent a simple and scalable strategy for the fabrication of Ce2(Mo4)3@g-C3N4 nanocomposites with controlled morphology.

[0007] Therefore, there is a need for a system configured to synthesize Ce 2(Mo4)3@g-C3N4 hybrid nanostructures as high-performance electrode materials for UA detection and providing a reliable, non-invasive and real-time monitoring platform for wearable biosensor technologies. SUMMARY OF THE INVENTION

[0008] The present disclosure relates to a system for the synthesis and fabrication of a cermolybdate graphitic carbon nitride nanocomposite (Ce2(Mo4)3@g-C3N4) for the detection of uric acid in sweat. The system overcomes the limitations of pure Ce2(Mo4)3, such as low conductivity and nanoparticle agglomeration, through its integration into g-C3N4 support materials. This enables a uniform distribution of active sites, improved charge transfer kinetics, and higher structural stability for wearable healthcare applications.

[0009] The present disclosure relates to a system for the synthesis and production of a cermolybdate / graphitic carbon nitride nanocomposite (Ce2(Mo4)3@g-C3N4) for the detection of uric acid in sweat. The system comprises: a cermolybdate synthesis unit for the production of Ce2(Mo4)3 nanoparticles by hydrothermal treatment. The synthesis unit consists of: a reaction vessel containing cerium nitrate and ammonium molybdate in a molar ratio of 2:3, dissolved in an ethanol-water mixture; a system for the addition of cetyltrimethylammonium bromide (CTAB) for stabilization; and a hydrothermal reactor that heats the mixture to 180 °C for 24 hours. The system further comprises a synthesis unit for graphitic carbon nitride, which produces g-C3N4 by thermal polymerization of melamine under an inert atmosphere at temperatures of 400 °C to 600 °C.The system further includes a nanocomposite formation unit that combines Ce2(Mo4)3 and g-C3N4 to form the nanocomposite Ce2(Mo4)3@g-C3N4. The nanocomposite formation unit includes an ultrasonic system for dispersing and interacting the components at the molecular level, as well as a drying system for removing residual solvents.

[0010] The subject of the present disclosure is a system for the synthesis and production of a cermolybdate / graphitic carbon nitride (Ce2 (Mo4)3@g-C3N4) nanocomposite for the detection of uric acid in sweat.

[0011] Another objective of the present disclosure is the synthesis of Ce2(Mo4)3@g-C3N4 nanocomposites that overcome the inherent limitations of pure Ce2(Mo4)3, including poor electronic conductivity and nanoparticle agglomeration, thereby achieving improved electrocatalytic activity for the detection of uric acid.

[0012] Another objective of the present disclosure is the production of electrochemical sensors with a detection limit of 6.2 µM for uric acid in sweat, which exhibit high selectivity, reproducibility and long-term operational stability under physiologically relevant conditions.

[0013] However, another objective of the present disclosure is to provide a scalable and cost-effective system that enables the integration of Ce2(Mo4)3@g-C3N4-based electrochemical sensors into portable diagnostic devices to ensure non-invasive real-time monitoring of uric acid for personalized healthcare and early disease detection.

[0014] To further clarify the advantages and features of the present disclosure, the invention is described in more detail with reference to specific embodiments illustrated in the accompanying drawings. It is understood that these drawings merely show typical embodiments of the invention and are therefore not to be understood as limiting its scope of protection. The invention is described and explained in more detail and with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE IMAGES

[0015] These and other features, aspects and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which identical symbols represent identical parts, wherein: Fig. Figure 1 shows a block diagram of a system for the synthesis and production of a cermolybdate graphitic carbon nitride (Ce2 (Mo4)3@g-C3N4) nanocomposite for the detection of uric acid in sweat according to an embodiment of the present disclosure; Fig. Figure 2 shows a block diagram of the electrochemical sensor according to an embodiment of the present disclosure; and Fig. Figure 3 shows a block diagram of a portable diagnostic system according to an embodiment of the present disclosure.

[0016] Furthermore, those skilled in the art will recognize that the elements in the drawings are simplified and not necessarily drawn to scale. For example, the flowcharts illustrate the process by highlighting the main steps to facilitate understanding of this disclosure. With regard to the construction of the device, one or more components may be represented in the drawings by conventional symbols. The drawings may show only those specific details relevant to understanding the embodiments of this disclosure, so as not to clutter the drawings with details that are already apparent to those skilled in the art from the description contained herein. DETAILED DESCRIPTION:

[0017] To facilitate understanding of the principles of the invention, reference is made below to the embodiment illustrated in the drawings, which is described using specific terms. It is understood, however, that this does not limit the scope of protection of the invention. Rather, modifications and further developments of the illustrated system, as well as further applications of the inventive principles depicted therein, are conceivable, insofar as they would typically occur to a person skilled in the art in the field of the invention.

[0018] It will be clear to those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not to be understood as a limitation of it.

[0019] References to “an aspect”, “another aspect”, or similar phrases in this description mean that a particular feature, structure, or property described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, phrases such as “in one embodiment”, “in another embodiment”, and similar expressions in this description may, but do not necessarily, all refer to the same embodiment.

[0020] The terms "includes," "comprehensive," or similar expressions denote non-exclusive inclusion. Thus, a procedure or method containing a list of steps does not only include those steps but may also include further steps not explicitly listed or inherent in the procedure or method. Likewise, the statement "includes..." for one or more devices, subsystems, elements, structures, or components, without further limitations, does not preclude the existence of other devices, subsystems, elements, structures, or components.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meanings generally known to those skilled in the art in the field to which this invention belongs. The systems, methods, and examples described herein serve only for illustration and are not to be understood as limiting.

[0022] Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0023] Fig. Figure 1 shows a block diagram of a system for the synthesis and production of a cerium-molybdate / graphitic carbon nitride (Ce 2(Mo4)3). @ g-C3N4) -nanocomposites for the detection of uric acid in sweat according to an embodiment of the present disclosure.

[0024] The system (100) according to Fig. 1 comprises: a cermolybdate synthesis unit (102) for the production of Ce2(Mo4)3 nanoparticles by hydrothermal treatment, wherein the cermolybdate synthesis unit (102) comprises: a reaction vessel (102a) containing cerium nitrate and ammonium molybdate in a molar ratio of 2:3, dissolved in a solvent mixture of ethanol and deionized water, a surfactant addition system (102b) for the addition of cetyltrimethylammonium bromide (CTAB) for stabilization, and a hydrothermal reactor (102c) for heating the mixture to 180 °C for 24 hours. The system (100) further comprises a synthesis unit (104) for graphitic carbon nitride, which produces g-C3N4 by thermal polymerization of melamine under an inert atmosphere at temperatures of 400 °C to 600 °C. The system (100) further comprises a nanocomposite formation unit (106) which combines Ce2 (Mo4)3 and g-C3N4 to form the nanocomposite Ce2 (Mo4)3@g-C3N4.The nanocomposite formation unit (106) comprises: an ultrasound system (106a) for dispersion and interaction of the components at the molecular level and a drying system (106b) for removal of residual solvents.

[0025] In one embodiment, the system (100) further comprises an electrochemical sensor manufacturing unit (108) configured to produce an electrochemical sensor using the Ce2(Mo4)3@g-C3N4 nanocomposite for the sensitive and selective detection of uric acid in sweat, wherein the electrochemical sensor comprises an electrode substrate and a sensor layer containing the Ce2(Mo4)3@g-C3N4 nanocomposite.

[0026] In one embodiment, the nanocomposite formation unit (106) is configured to dissolve 30 mg Ce 2(Mo4)3 in 20 mL of a solvent mixture of 10 mL ethanol and 10 mL deionized water and to disperse 10 mg g-C3N4 in 20 mL of the same solvent system.

[0027] In one embodiment, the ultrasound system of the nanocomposite formation unit (106) is configured to sonicate the combined Ce 2(Mo4)3 and g-C3N4 solutions for 3 hours to ensure uniform dispersion and interaction at the molecular level.

[0028] In one embodiment, the drying system of the nanocomposite formation unit (106) is configured such that the sonicated mixture is dried for 12 hours in a hot air oven at 70°C.

[0029] In one embodiment, the cermolybdate synthesis unit (102) is configured to perform centrifugation and washing of the yellow precipitate with deionized water, followed by vacuum drying at 70°C for 24 hours.

[0030] In one embodiment, the graphite-carbon nitride synthesis unit (104) is configured to carry out thermal polymerization under a nitrogen or argon atmosphere to prevent oxidation during synthesis.

[0031] In one embodiment, the Ce2(Mo4)3@g-C3N4 nanocomposite is configured to offer improved conductivity compared to pure Ce 2(Mo4)3 and to prevent the agglomeration of nanoparticles.

[0032] In one embodiment, the system (100) further comprises a characterization unit (110) configured to perform performance tests of the manufactured electrochemical sensor. The characterization unit (110) includes devices for measuring selectivity, reproducibility, and operational stability under physiologically relevant conditions.

[0033] In one embodiment, the system is configured so that the electrochemical sensor can be integrated into portable medical devices for real-time monitoring of uric acid concentration in sweat.

[0034] The present invention offers a comprehensive system for addressing the key challenges of non-invasive uric acid measurement through a novel synthesis and fabrication approach. The system enables the fabrication of Ce2(Mo4)3@g-C3N4 hybrid nanocomposites, where graphitic carbon nitride forms a large-surface-area conductive scaffold that prevents nanoparticle agglomeration and accelerates charge transfer kinetics. The cermolybdate synthesis unit undergoes hydrothermal treatment at 180 °C for 24 hours with CTAB stabilization, while the graphitic carbon nitride synthesis unit performs the thermal polymerization of melamine under an inert atmosphere. The nanocomposite formation unit integrates these components through controlled sonication for 3 hours, followed by drying at 70 °C, ensuring uniform dispersion and interaction at the molecular level.The resulting system generates electrochemical sensors capable of detecting uric acid with a detection limit of 6.2 µM, significantly outperforming conventional Ce2(Mo4)3-based systems. Specifically designed for integration into wearable health devices, the system enables continuous, non-invasive monitoring of metabolic biomarkers for personalized health management and the early detection of metabolic and kidney diseases.

[0035] In one embodiment, a Ce2(Mo4)3@g-C3N4-based hybrid nanocomposite material is provided that effectively enhances the electrochemical performance for the sensitive and selective detection of uric acid (UA) in sweat for non-invasive health monitoring. The invention further provides a highly sensitive, stable, and cost-effective electrochemical biosensor that enables real-time UA detection in artificial sweat. By integrating Ce2(Mo4)3 into graphitic carbon nitride (g-C3N4), the invention aims to create a synergistic nanostructure with improved electron transfer, uniform nanoparticle dispersion, and increased availability of active sites for UA sensor applications. The invention utilizes a simple hydrothermal synthesis method to produce Ce2(Mo4)3 nanoparticles anchored to g-C3N4 nanosheets, thus forming a homogeneous hybrid nanocomposite.In this system, Ce2 (Mo4)3 provides numerous redox-active centers, which are formed from the variable oxidation states of Ce (Ce. 3+ / Ce 4+ ) and Mon (Mon 6+) and are crucial for uric acid oxidation reactions. Simultaneously, g-C3N4 serves as a conductive two-dimensional support that enhances charge transport, suppresses particle agglomeration, and maximizes the exposure of catalytic centers. The synergistic interaction between Ce2(Mo4)3 and g-C3N4 leads to accelerated electron transfer kinetics, reduced charge transfer resistance, and improved structural stability under physiological conditions. By developing this hybrid nanostructure, the invention significantly lowers the detection limit for uric acid (down to 6.2 µM in artificial sweat) and ensures high selectivity, reproducibility, and long-term stability. The proposed material offers a scalable and environmentally friendly approach for the development of advanced biosensors designed for wearable health technologies.

[0036] The present system is used for the synthesis and fabrication of a cermolybdate / graphitic carbon nitride nanocomposite (Ce2(Mo4)3@g-C3N4) for the detection of uric acid in sweat. The system consists of several integrated units configured for the sequential synthesis, combination, and fabrication of the Ce2(Mo4)3@g-C3N4 nanocomposite with improved structural, morphological, and electrochemical properties, making it suitable for sensor applications.

[0037] In one embodiment, the cermolybdate synthesis unit of the system is configured to produce Ce₂(MoO₄)₃ nanoparticles via a controlled hydrothermal process. The cermolybdate synthesis unit comprises a reaction vessel in which 2 mmol of cerium nitrate is dissolved in a solvent mixture of 20 mL ethanol and 20 mL deionized water, creating a homogeneous solution. The system further includes a drop-feed mechanism that adds this cerium nitrate solution to a separate ammonium molybdate solution (3 mmol) in 40 mL of the same solvent mixture, thus maintaining the 2:3 molar ratio between cerium and molybdate ions. A surfactant addition system serves to add cetyltrimethylammonium bromide (CTAB) as a stabilizer to prevent agglomeration and ensure uniform nucleation of the Ce₂(MoO₄)₃ particles.The resulting solution is then transferred to a Teflon-coated stainless steel autoclave, part of a hydrothermal reactor. This heats the mixture to 180 °C for 24 hours, enabling crystal growth and particle formation under controlled pressure and temperature conditions. After completion of the hydrothermal treatment, the system cools the autoclave to room temperature. The resulting yellow precipitate is then separated by centrifugation in the cermolybdate synthesis unit and washed several times with deionized water to remove unreacted residues and impurities. The washed product is then transferred to a vacuum drying system, which dries the material at 70 °C for 24 hours. The result is a pure, dry cermolybdate powder (Ce₂(MoO₄)₃) ready for composite formation.

[0038] The synthesis unit for graphitic carbon nitride (g-C3N4) is configured to synthesize g-C3N4 by thermal polymerization of melamine under controlled inert gas conditions. Melamine powder is introduced into a reaction chamber or crucible designed for high temperatures and inert atmospheres. The synthesis unit is equipped with an inert gas flow system that supplies nitrogen or argon to prevent oxidation during polymerization. The unit's temperature control system gradually increases the temperature from 400 °C to 600 °C, ensuring a uniform heating profile. During this heat treatment, melamine undergoes condensation reactions, releasing ammonia and water vapor, and forming polymeric carbon nitride chains. The process continues until a well-defined g-C3N4 structure is formed, which is either crystalline or amorphous depending on the synthesis conditions.The resulting g-C3N4 material exhibits a layer morphology with a high nitrogen content and is suitable as a substrate for subsequent nanocomposite formation.

[0039] The system's nanocomposite formation unit is configured to integrate the synthesized Ce2(Mo4)3 nanoparticles with g-C3N4 to form the Ce2(Mo4)3@g-C3N4 nanocomposite. For this purpose, 30 mg of Ce2(Mo4)3 are dissolved in 20 ml of a solvent mixture consisting of 10 ml of ethanol and 10 ml of deionized water. Separately, 10 mg of g-C3N4 is dispersed in 20 ml of the same solvent system to ensure uniform distribution of the nanosheets. The system employs an ultrasonic system that blends the Ce2(Mo4)3 and g-C3N4 solutions and sonicates the resulting mixture for 3 hours. This process promotes effective dispersion and molecular-level interaction between the Ce2(Mo4)3 nanoparticles and the g-C3N4 nanosheets, resulting in a homogeneous nanocomposite with strong interfacial bonding.After ultrasonic treatment, the resulting mixture is dried for 12 hours at 70 °C in a hot air oven within the drying unit of the nanocomposite production facility to remove residual solvents and moisture. The result is a Ce2(Mo4)3@g-C3N4 nanocomposite with improved conductivity, increased surface area, and enhanced structural stability, suitable for the fabrication and subsequent characterization of electrochemical sensors.

[0040] Fig. Figure 2 shows a block diagram of the electrochemical sensor according to an embodiment of the present disclosure.

[0041] Fig. The electrochemical sensor shown in Figure 2 consists of an electrode substrate and a sensor layer made of the nanocomposite Ce2(Mo4)3@g-C3N4. It is configured to detect uric acid in sweat with high sensitivity and selectivity. Glassy carbon electrodes, screen-printed electrodes, or flexible, conductive substrates suitable for integration into portable devices can be used as electrode substrates. The method for determining uric acid in sweat involves contacting a sweat sample or artificial sweat with the electrochemical sensor, applying an electrochemical potential, and detecting a current response proportional to the uric acid concentration. The method achieves a detection limit of approximately 6.2 µM and exhibits high selectivity even in the presence of interfering substances such as glucose, ascorbic acid, and lactate.

[0042] Fig. Figure 3 shows a block diagram of a portable diagnostic system according to an embodiment of the present disclosure.

[0043] According to Fig. 3. The portable diagnostic system comprises the following: a flexible substrate, an electrochemical sensor integrated on this substrate, and an electronic interface configured to record and transmit uric acid concentration data in real time, enabling non-invasive and continuous monitoring of uric acid for personalized healthcare and early detection of metabolic and kidney diseases.

[0044] The structural, compositional and electrochemical characterization of the produced CeMo, g-C3N4 and CeMo@g-C3N 4 materials confirmed the successful synthesis and integration of the nanocomposite with desirable physicochemical and sensory properties.

[0045] X-ray diffraction (XRD) analysis of CeMo nanocomposites synthesized at different cerium-molybdenum ratios revealed distinct diffraction peaks corresponding to the Ce₂(MoO₄)₃ planes, consistent with data from JCPDS 30-0303. This confirms the successful formation of the CeMo phase. The prominent peaks at 18.87°, 26.36°, 30.24°, 34.8°, 38.25°, and 47.05° demonstrated the crystalline nature of Ce₂(MoO₄)₃. Minor peak shifts were observed, suggesting slight lattice distortions and the introduction of oxygen vacancies due to compositional variations. The CeMo@g-C3N4 composites showed diffraction peaks that are characteristic of both Ce2 (MoO4)3 and g-C3N4, confirming the formation of a hybrid structure.The presence of the Ce2 (MoO4)3 peaks together with those of g-C3N4 indicated a successful incorporation of g-C3N4 without phase destruction, suggesting an increased surface area, increased catalytic efficiency and improved charge transfer capability.

[0046] Infrared (IR) spectroscopy showed characteristic absorption bands at 476 cm. -1 , 813 cm -1 and 1630 cm -1The vibrations can be attributed to metal-oxygen vibrations (Ce-O or Mo-O) and CN or HO bending vibrations. This confirms the presence of CeMo and g-C3N4 components in the nanocomposite. Thermogravimetric analysis (TGA) revealed a gradual mass loss from 30 °C to 800 °C without an abrupt drop, indicating high thermal stability and strong structural integrity of the composite. The observed moderate decrease was attributed to the slow decomposition of residual organic components and confirms the effective incorporation of g-C3N4 into the CeMo matrix.

[0047] X-ray photoelectron spectroscopy (XPS) confirmed the elemental composition and oxidation states of Ce, Mo, C, N, and O in the composite material. The Mo 3d peaks at 226.53 eV, 229.28 eV, and 232.42 eV corresponded to Mo 6+ , while the Ce 3d peaks are at 882.37 eV, 886.7 eV, 900.41 eV and 904.81 eV Ce 3+The chemical states were confirmed. The C 1s spectra showed peaks at 284.02 eV (CC / CH) and 288.18 eV (CN), while the N 1s spectra exhibited peaks at 398.03 eV and 400.03 eV, confirming the CNC and NC=N bonds in g-C3N4. The O 1s spectra showed peaks at 529.1 eV, 531.2 eV, and 532.4 eV, which could be assigned to lattice oxygen, hydroxyl groups, and adsorbed oxygen species, respectively. These results, taken together, confirmed the chemical integrity and bonding in the CeMo@g-C3N4 composite.

[0048] Transmission electron microscopy (TEM) revealed that CeMo particles exhibited a cuboidal morphology with well-defined crystal edges. In the CeMo@g-C3N4 composite, these cuboidal CeMo particles were well dispersed and integrated into the hexagonal, sheet-like structure of g-C3N4, indicating strong interfacial interactions. The surface electron diffraction (SAED) pattern of CeMo showed crystal rings, while that of CeMo@g-C3N4 exhibited polycrystalline features. This confirmed the hybrid nature and structural coherence of the composite.

[0049] Electrochemical investigations using cyclic voltammetry (CV) and impedance spectroscopy showed that CeMo with a cerium-molybdenum ratio of 2:3 exhibited the highest current response and fastest charge transfer, confirming its superior electrochemical performance compared to the other tested ratios. The incorporation of g-C3N4 resulted in a further improvement in current response and reversibility, as well as reduced impedance, indicating efficient charge transfer and higher conductivity. These results confirmed that the CeMo@g-C3N4 composite exhibits superior electrochemical properties compared to pure CeMo and bare electrodes.

[0050] The sensor's performance in uric acid measurement showed a single irreversible oxidation peak, with the current increasing linearly with the scan speed (R). 2= 0.92). Differential pulse voltammetry (DPV) measurements showed a linear relationship between the uric acid concentration (0.1-120 µM) and the current intensity (R). 2 = 0.95) with a detection limit of approximately 6.2 µM, confirming high sensitivity. Amperometric interference studies showed a maximum current for uric acid, while other analytes generated significantly lower signals, demonstrating excellent selectivity.

[0051] Stability testing revealed a gradual decrease in the CV response from 100% to 90% after 50 cycles, while the DPV stability decreased from 95% to 90%, indicating nonlinear degradation patterns. Recovery studies with uric acid concentrations of 25, 50, and 75 µM showed consistent recovery between 80% and 85%, thus confirming the reliability and robustness of the sensor under practical detection conditions. In summary, these results demonstrate that the CeMo@g-C3N4 nanocomposite exhibits high structural stability, excellent electrochemical activity, strong selectivity, and reproducible sensor properties for uric acid detection.

[0052] The system for synthesizing and fabricating the electrochemical sensor based on a cermolybdate / graphitic carbon nitride (Ce2(Mo4)3@g-C3N4) nanocomposite exhibits several superior electrocatalytic and functional advantages, making it ideally suited for detecting uric acid in sweat and for integration into wearable health monitoring systems. The fabricated Ce2(Mo4)3@g-C3N4 hybrid sensor is characterized by high sensitivity and a low detection limit of approximately 6.2 µM, surpassing the performance of pure Ce2(Mo4)3 and conventional enzyme-based uric acid sensors. This enhanced sensitivity and reliability are achieved through the synergistic combination of the redox-active Ce2(Mo4)3 nanoparticles with the conductive and chemically stable g-C3N4 support.The improved conductivity of the g-C3N4 matrix significantly enhances electron transport within the sensor interface, reduces charge transfer resistance, and accelerates the oxidation kinetics of uric acid, resulting in faster electrochemical reaction times. The electrochemical sensor produced with this system also exhibits excellent selectivity, enabling precise uric acid measurement even in the presence of common interfering substances such as glucose, ascorbic acid, and lactate, which are typically found in sweat. Furthermore, the Ce2(Mo4)3@g-C3N4 sensor demonstrates long-term stability and reproducibility, maintaining its performance over multiple electrochemical cycles without significant degradation. This overcomes the limitations of enzyme-based biosensors, which often suffer from instability, temperature dependence, and limited shelf life.

[0053] The presented system represents a significant technological advancement in the development and fabrication of non-enzymatic electrochemical biosensors. By combining the versatile redox properties of Ce2(Mo4)3 with the exceptional electronic conductivity and chemical stability of g-C3N4, the system offers a robust and high-performance sensor platform that ensures reliable operation under a wide range of physiological and environmental conditions. The hybrid nanostructure developed within the system ensures a uniform distribution of active sites, improved charge transfer kinetics, and superior structural stability, thus enabling highly efficient and reproducible electrochemical sensing.

[0054] The system is also scalable and industrially feasible, offering a cost-effective platform for the large-scale production of nanocomposite-based biosensors. The environmentally friendly hydrothermal and thermal synthesis processes employed in the cermolybdate synthesis unit, the graphite-carbon nitride synthesis unit, and the nanocomposite formation unit make the process sustainable and economically attractive.

[0055] The fabricated electrochemical sensor exhibits remarkable performance in uric acid determination with high selectivity, reproducibility, and operational stability under physiologically relevant conditions. The synergistic interaction between the redox-active centers of Ce2(Mo4)3 and the conductive g-C3N4 network improves the overall electrocatalytic activity and durability of the sensor compared to pure Ce2(Mo4)3.

[0056] From an industrial perspective, the system offers a versatile and scalable pathway for developing next-generation wearable diagnostic devices capable of continuously monitoring uric acid and other metabolic biomarkers in sweat. The sensor's integrability with flexible substrates and wearable electronics systems makes the technology a key enabler for personalized healthcare, fitness monitoring, and preventive medicine. Furthermore, the presented system enables cost-effective, high-performance, and non-invasive biomarker detection using readily available and environmentally friendly materials. Beyond uric acid measurement, the nanocomposite design and synthesis strategy developed with the system can be extended to other analytes and metabolites, thus expanding its applications in health diagnostics, personalized medicine, and real-time health monitoring.Thus, the system represents a significant technological contribution to the fields of electrochemical biosensors, wearable technology and non-invasive health diagnostics, and offers an advanced, robust and scalable solution for next-generation biomedical sensor applications.

[0057] The drawings and the preceding description illustrate embodiments. Those skilled in the art will recognize that one or more of the described elements can be combined to form a single functional element. Alternatively, certain elements can be divided into several functional elements. Elements of one embodiment can be added to another. For example, the process flows described here can be modified and are not limited to the manner described herein. Furthermore, the actions of a flowchart need not be performed in the sequence shown; nor do all actions necessarily need to be carried out. Actions that do not depend on other actions can be performed in parallel with the other actions. The scope of protection of the embodiments is in no way limited by these specific examples. Numerous variations, whether explicitly stated in the description or not, such as...

[0058] Differences in structure, dimensions, and materials are possible. The scope of protection of the embodiments is at least as comprehensive as described by the following claims.

[0059] The advantages, other benefits, and problem solutions have been described above with reference to specific embodiments. However, the advantages, benefits, problem solutions, and any components that can effect or enhance an advantage, benefit, or solution are not to be construed as critical, necessary, or essential features or components of the claims. REFERENCES 100 A system for the synthesis and production of a cerium molybdate / graphitic carbon nitride (Ce2(Mo4)3@g-C3N4) nanocomposite for the detection of uric acid in sweat. 102 Synthesis unit 102a Reaction vessel 102b Surfactant Additive System 102c Hydrothermal Reactor 104 Graphitic carbon nitride synthesis plant 106 Nanocomposite formation unit 106a Ultrasound system 106b Drying system 108 Manufacturing Unit for Electrochemical Sensors 110 Characterization Unit 202 Electrode substrate 204 Sensor layer 206 Ce2 (Mo4)3@G-C3N4 nanocomposite 302 Flexible Substrate 304 Electrochemical Sensor 306 Electronic interface

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