Description:DEVELOPMENT OF PHOTOCATALYTIC SENSORS FOR REAL-TIME MONITORING OF AIR AND WATER QUALITY
Field of the Invention
[0001] The disclosure relates to photocatalytic sensors for real-time detection of contaminants in air and water using semiconductor-activated reactive interfaces.
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] Existing air and water quality monitoring systems often rely on large-scale analytical instruments such as gas chromatographs, spectrophotometers, or mass spectrometers, which, while offering high accuracy, are typically confined to centralized laboratory environments due to their complexity, cost, and need for skilled operation. Many commercially available sensor nodes, though more portable, lack the sensitivity or selectivity required for detecting trace-level pollutants in complex environmental matrices. Traditional chemical sensors often exhibit limited durability, suffer from drift, and cannot regenerate themselves for long-term operation. Recent advances in nanomaterials and photocatalysis have opened new avenues for pollutant sensing by leveraging light-activated reactions to detect or degrade harmful substances. However, the integration of such photocatalytic materials into miniaturized, low-power, field-deployable sensor architectures remains challenging. Prior art in this domain either neglects the dual capacity of photocatalytic surfaces to simultaneously react and signal the presence of contaminants, or fails to incorporate real-time signal conditioning and remote communication infrastructure. There remains a substantial need for an integrated system that utilizes photocatalytic activity as both a detection and degradation mechanism, combined with advanced signal interpretation and remote accessibility. Furthermore, challenges such as rapid fouling, low signal-to-noise ratios, or instability under variable environmental conditions hinder widespread adoption. Thus, the current disclosure addresses the critical gap in developing a robust, miniaturized, photocatalytic sensor for real-time environmental monitoring of both air and water matrices.
[0004] 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.
[0005] It also shall be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. This invention can be achieved by means of hardware including several different elements or by means of a suitably programmed computer. In the unit claims that list several means, several ones among these means can be specifically embodied in the same hardware item. The use of such words as first, second, third does not represent any order, which can be simply explained as names.
Summary
[0006] Various objects, features, and advantages of the disclosed subject matter can be more fully appreciated with reference to the following detailed description of the disclosed subject matter when considered in connection with the following drawings, in which like reference numerals identify like elements.
[0007] The disclosure relates to photocatalytic sensors for real-time detection of contaminants in air and water using semiconductor-activated reactive interfaces.
[0008] The present disclosure pertains to a photocatalytic sensor system designed for real-time monitoring of air and water quality through the application of light-activated semiconductor materials and integrated electronic sensing. The system comprises a reaction chamber structured to expose environmental fluid samples to a photocatalytic substrate under controlled illumination. The substrate is coated with a semiconducting metal oxide, such as titanium dioxide, optionally doped to expand spectral responsiveness. Pollutants present in the sample undergo photochemical transformation upon contact with the illuminated substrate, resulting in reactive species such as hydroxyl radicals or superoxide ions. These intermediate products or resulting redox shifts are sensed by an electrode array positioned downstream of the substrate layer. A signal processing unit collects electrical responses from the sensing electrode arrangement and processes the signals using embedded filtering and recognition algorithms. The sensor system may further include a calibration module, allowing injection of standard pollutant solutions for self-diagnostics and baseline adjustment. The architecture includes a wireless communication interface for cloud-based visualization and data logging. The fluid handling pathway within the system can employ microfluidic geometries to ensure consistent residence time and maximize interaction with the photocatalytic surface. Additionally, an adaptive illumination source enables wavelength tuning to optimize reaction conditions for specific pollutants. The system operates as a closed-loop structure, allowing continuous, unattended environmental monitoring, with the capability to differentiate between pollutant types using trained signal recognition algorithms. Overall, the system merges photocatalytic surface chemistry, miniaturized electrochemical detection, digital signal interpretation, and wireless communication into a cohesive environmental sensing platform.
Brief Description of the Drawings
[0009] The features and advantages of the present disclosure would be more clearly understood from the following description taken in conjunction with the accompanying drawings in which:
[00010] FIG. 1 illustrates a system architecture diagram depicting the structural interconnection of the primary functional components constituting the photocatalytic sensor system for real-time air and water quality monitoring, including the reaction chamber, light source, sensing electrodes, signal processing unit, and wireless communication module.
[00011] FIG. 2 illustrates a method flow diagram representing the procedural stages involved in the operational workflow of the photocatalytic sensor system, including sample intake, photocatalytic activation, reactive species detection, signal processing, pollutant identification, and data transmission.
[00012] FIG. 3 illustrates a data flow diagram delineating the digital and analog signal pathways from pollutant sensing to cloud-based data archiving, including calibration data paths and integration with machine learning-based pollutant classification algorithms.
Detailed Description
[00013] The following is a detailed description of exemplary embodiments to illustrate the principles of the invention. The embodiments are provided to illustrate aspects of the invention, but the invention is not limited to any embodiment. The scope of the invention encompasses numerous alternatives, modifications and equivalent; it is limited only by the claims.
[00014] In view of the many possible embodiments to which the principles of the present discussion may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of the claims. Therefore, the techniques as described herein contemplate all such embodiments as may come within the scope of the following claims and equivalents thereof.
[00015] Throughout the present disclosure, the term “network” relates to an arrangement of interconnected programmable and/or non-programmable components that are configured to facilitate data communication between one or more electronic devices and/or databases, whether available or known at the time of filing or as later developed. Furthermore, the network may include, but is not limited to, one or more peer-to-peer network, a hybrid peer-to-peer network, local area networks (LANs), radio access networks (RANs), metropolitan area networks (MANS), wide area networks (WANs), all or a portion of a public network such as the global computer network known as the Internet, a private network, a cellular network and any other communication system or systems at one or more locations.
[00016] Throughout the present disclosure, the term “process”* relates to any collection or set of instructions executable by a computer or other digital system so as to configure the computer or the digital system to perform a task that is the intent of the process.
[00017] Throughout the present disclosure, the term ‘Artificial intelligence (AI)’ as used herein relates to any mechanism or computationally intelligent system that combines knowledge, techniques, and methodologies for controlling a bot or other element within a computing environment. Furthermore, the artificial intelligence (AI) is configured to apply knowledge and that can adapt it-self and learn to do better in changing environments. Additionally, employing any computationally intelligent technique, the artificial intelligence (AI) is operable to adapt to unknown or changing environment for better performance. The artificial intelligence (AI) includes fuzzy logic engines, decision-making engines, preset targeting accuracy levels, and/or programmatically intelligent software.
[00018] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different instances in the description and the figures may indicate similar or identical items.
[00019] Pursuant to the "Detailed Description" section herein, whenever an element is explicitly associated with a specific numeral for the first time, such association shall be deemed consistent and applicable throughout the entirety of the "Detailed Description" section, unless otherwise expressly stated or contradicted by the context.
[00020] The disclosure relates to photocatalytic sensors for real-time detection of contaminants in air and water using semiconductor-activated reactive interfaces.
[00021] Pursuant to the "Detailed Description" section herein, whenever an element is explicitly associated with a specific numeral for the first time, such association shall be deemed consistent and applicable throughout the entirety of the "Detailed Description" section, unless otherwise expressly stated or contradicted by the context.
[00022] FIG. 1 illustrates a system architecture representation for a photocatalytic sensor system engineered for real-time monitoring of air and water quality using photo-induced semiconductor surface reactions, electronic sensing arrays, and digital signal processing. The central component is the reaction chamber, which includes a photocatalytic substrate layer deposited with a semiconducting metal oxide material. An illumination source is optically aligned with the substrate to activate the semiconductor’s surface by supplying ultraviolet or visible-range photons, thereby initiating the formation of electron-hole pairs. The fluid inlet allows either air or water samples to be directed through the reaction chamber, where pollutants encounter the activated photocatalytic surface and undergo chemical transformation. Downstream of the substrate, a sensing electrode array is placed to detect electrical variations corresponding to transient redox products or reactive oxygen species. This electrode array is connected to a signal processing unit comprising an analog-to-digital converter, microcontroller, filtering logic, and pollutant threshold algorithms. A wireless transmission module is integrated into the signal processing unit to relay processed data to a cloud-based system using Wi-Fi, LoRa, or cellular networks. The system is designed to operate in real-time with continuous sample flow and automatic calibration options. The architecture emphasizes a compact yet modular layout suitable for integration into diverse monitoring scenarios, providing synergistic interaction between chemical sensing, signal digitization, and remote analytics. The disclosed photocatalytic sensor system for real-time air and water quality monitoring comprises a series of interdependent modules arranged to synergistically detect, classify, and transmit data related to the presence of environmental contaminants through photocatalytically induced reactions and corresponding electrical signal variations. The reaction chamber includes a substrate layer coated with a semiconducting metal oxide, such as titanium dioxide, configured to undergo excitation upon exposure to ultraviolet or visible light. The excitation leads to the generation of electron-hole pairs that interact with surrounding air or water molecules introduced via a fluid inlet, leading to the production of hydroxyl radicals, superoxide ions, or other reactive oxygen species. These species react with pollutants present in the environmental sample, breaking them down and simultaneously altering the electrical characteristics measurable at the downstream sensing electrode arrangement.
[00023] The sensing electrode arrangement comprises interdigitated electrodes coated with conductive polymers capable of capturing transient redox activity. The sensing configuration is interfaced with a signal processing unit which includes analog-to-digital conversion, digital filtering, baseline normalization, and adaptive calibration subroutines. Real-time pollutant concentration data are interpreted and optionally tagged with location and timestamp metadata before being wirelessly transmitted to a cloud dashboard via integrated modules supporting Wi-Fi or cellular protocols. A tunable wavelength LED or laser diode array serves as the illumination source, allowing the system to adaptively target specific activation wavelengths corresponding to the absorption characteristics of the photocatalytic material and the expected pollutant class.
[00024] In an alternative embodiment, the substrate layer is configured as a nanoporous ceramic membrane possessing high thermal and chemical stability. The membrane is fabricated through sol-gel processing or atomic layer deposition to achieve controlled porosity and surface area. This allows maximal contact between the fluid stream and the active catalytic surface while maintaining low backpressure. The nanoporous membrane supports long-term durability and allows integrated flow-through operation in field conditions.
[00025] In a second embodiment, the fluid flow path adopts a microfluidic serpentine design fabricated using soft lithography or laser micromachining in PDMS or other polymeric substrates. The channel walls are coated with the photocatalytic material, allowing longitudinal interaction of the flowing sample with activated surfaces. This configuration enables reduced dead volume, faster response time, and higher signal fidelity due to consistent analyte residence time. Real-time sensor data is fed to a machine learning module integrated within the signal processing unit, which matches incoming signal patterns with pollutant-specific profiles to improve classification accuracy under dynamic environmental conditions.
[00026] In a third embodiment, a calibration module is included comprising a fluidic valve matrix and reservoirs containing standardized solutions of known pollutant concentrations. Under predetermined intervals or when signal drift is detected, the system automatically switches fluid intake to the calibration standard, executes signal normalization routines, and adjusts detection thresholds based on error margins. This self-correcting capability enhances long-term operational stability without manual recalibration.
[00027] The data processing flow involves multiple real-time operations including analog signal acquisition from the sensor array, conversion to digital format, normalization against calibration baselines, spectral pattern recognition using pre-trained models, assignment of pollutant identity and concentration, and packaging of the result set for wireless transmission. In certain deployments, the system is configured to trigger alerts or activate auxiliary remediation systems upon detection of thresholds exceeding environmental safety limits.
[00028] Under alternative deployment scenarios, the sensor may be embedded in aquatic monitoring buoys, industrial exhaust ducts, or wearable devices for occupational exposure tracking. The system’s modular design allows integration with existing telemetry frameworks and environmental data networks. Through consistent feedback from real-world samples and over-the-air algorithm updates, the system continually enhances pollutant identification confidence.
[00029] The holistic architecture and operational protocol of the disclosed sensor system demonstrate a synergistic integration of photocatalytic chemistry, miniaturized fluidics, signal digitization, adaptive calibration, and intelligent analytics, enabling reliable, continuous environmental monitoring suitable for urban, industrial, or remote field applications.
[00030] FIG. 2 represents a method flow diagram highlighting the sequential operational stages of the disclosed photocatalytic sensor system, facilitating accurate and timely environmental monitoring. The procedure begins with environmental sample intake, wherein either ambient air or water is channeled into the reaction chamber through a fluid inlet mechanism. The photocatalytic surface is simultaneously exposed to a tunable illumination source, initiating photon-induced electron-hole pair generation. As the sample flows over the activated semiconductor layer, photocatalytic reactions occur, transforming target pollutants into detectable chemical species such as hydroxyl radicals. These transformed species alter the local electrochemical environment, which is then sensed by an interdigitated electrode array positioned at the exit of the reaction zone. The electrical signal generated at this interface is acquired and digitized within the signal processing unit. Signal refinement procedures such as baseline correction and dynamic thresholding are performed. The processed signals are subjected to pollutant classification algorithms that output pollutant identities and concentrations. In subsequent steps, the signal is packaged with associated metadata and transmitted wirelessly to a cloud dashboard for visualization and archival. The method ensures continuous loop operation with intermittent calibration steps wherein standard pollutant samples are routed into the system to maintain analytical accuracy.
[00031] FIG. 3 illustrates a data flow diagram defining the information transmission pathways and computational processes within the photocatalytic sensor platform, with emphasis on signal propagation, calibration control, machine learning inference, and remote data handling. Sensor signals originating from the electrode array are transmitted to an analog front end for preprocessing, including gain amplification and noise suppression. The analog signal is then digitized and passed into the microcontroller-based signal processing block. Here, digital filtering, normalization, and spectral pattern extraction algorithms are applied. Processed data is routed in two parallel directions: one toward the machine learning engine trained with pollutant-specific signal patterns, and the other toward a calibration control module. The calibration module operates by intermittently initiating a controlled switch to a standard pollutant reservoir, recording response differentials, and applying correction factors. Inference results from the machine learning module are tagged with timestamps and geolocation data from a system-integrated GPS unit. Final data packets are transferred to a wireless transmission interface and delivered to cloud services for storage, visualization, and optional alert generation. The data flow structure enables precise, self-correcting, and intelligent pollutant tracking within dynamic environmental contexts.
[00032] The above description is intended to be illustrative, and not restrictive. Although the present disclosure has been described with references to specific illustrative examples and implementations, it will be recognized that the present disclosure is not limited to the examples and implementations described. The scope of the disclosure should be determined with reference to the following claims, along with the full scope of equivalents to which the claims are entitled.
[00033] Modifications, additions, or omissions may be made to the systems and apparatuses described herein without departing from the scope of the disclosure. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. Additionally, operations of the systems and apparatuses may be performed using any suitable logic comprising software, hardware, and/or other logic. As used in this document, “each” refers to each member of a set or each member of a subset of a set.
[00034] The term “memory,” as used herein relates to a volatile or persistent medium, such as a magnetic disk, or optical disk, in which a computer can store data or software for any duration. Optionally, the memory is non-volatile mass storage such as physical storage media. Furthermore, a single memory may encompass and in a scenario wherein computing system is distributed, the processing, memory and/or storage capability may be distributed as well.
[00035] Throughout the present disclosure, the term ‘server’ relates to a structure and/or module that include programmable and/or non-programmable components configured to store, process and/or share information. Optionally, the server includes any arrangement of physical or virtual computational entities capable of enhancing information to perform various computational tasks.

Claims
I/We Claim:
CLAIM 1.
A photocatalytic sensor system for real-time monitoring of air and water quality, comprising: a photocatalytic reaction chamber including a substrate layer coated with a semiconducting metal oxide; an ultraviolet or visible light illumination source positioned to irradiate said substrate layer to activate said semiconducting metal oxide; a fluid inlet configured to introduce an environmental sample comprising air or water into the photocatalytic reaction chamber; a sensing electrode arrangement positioned downstream of the substrate layer and configured to detect reactive species generated through photocatalytic reactions; and a signal processing unit operatively connected to the sensing electrode arrangement, said signal processing unit being configured to interpret electrical changes corresponding to variations in pollutant concentrations within the environmental sample.
CLAIM 2.
The photocatalytic sensor system as claimed in claim 1, wherein said semiconducting metal oxide comprises titanium dioxide doped with transition metals or rare earth elements to extend photocatalytic activity into the visible spectrum and enhance detection sensitivity for volatile organic compounds or dissolved chemical contaminants.
CLAIM 3.
The photocatalytic sensor system as claimed in claim 1, wherein said sensing electrode arrangement comprises an array of interdigitated electrodes coated with conductive polymer films, said arrangement being configured to detect transient oxidation or reduction products formed on the substrate layer due to photocatalytic decomposition of airborne or waterborne pollutants.
CLAIM 4.
The photocatalytic sensor system as claimed in claim 1, wherein said signal processing unit comprises a microcontroller interfaced with an analog-to-digital converter, said microcontroller being configured to implement digital filtering, baseline correction, and pollutant-specific threshold algorithms to enable real-time quantitative detection and classification of chemical species.
CLAIM 5.
The photocatalytic sensor system as claimed in claim 1, further comprising a data transmission module integrated with said signal processing unit, said module being configured to wirelessly transmit pollutant concentration data to a cloud-based dashboard via Wi-Fi, LoRa, or cellular network for remote visualization and archival.
CLAIM 6.
The photocatalytic sensor system as claimed in claim 1, wherein said reaction chamber comprises a microfluidic architecture having a serpentine or spiral flow path, said architecture being configured to prolong residence time of the environmental sample within the illuminated region, thereby increasing reaction efficiency and sensitivity.
CLAIM 7.
The photocatalytic sensor system as claimed in claim 1, wherein said substrate layer is a nanoporous glass, ceramic, or polymer membrane impregnated with the semiconducting metal oxide, said membrane being configured to facilitate high surface area interactions with the fluid sample while maintaining mechanical integrity and minimizing flow resistance.
CLAIM 8.
The photocatalytic sensor system as claimed in claim 1, further comprising a calibration module including a reservoir containing known concentrations of standard pollutants, a selector valve operatively coupled to said fluid inlet, and an algorithm within said signal processing unit to dynamically correct sensor drift and measurement variance by periodically introducing said standards.
CLAIM 9.
The photocatalytic sensor system as claimed in claim 1, wherein said illumination source includes a tunable wavelength emitter capable of selectively activating photocatalytic reactions at desired energy bands, thereby enabling selective detection of specific pollutants based on their photoreaction kinetics with the coated semiconducting surface.
CLAIM 10.
The photocatalytic sensor system as claimed in claim 1, wherein said signal processing unit is operatively configured to integrate machine learning models trained on pollutant-specific spectral response datasets, said models being configured to predict and classify types and concentrations of pollutants with increased confidence based on real-time sensor data patterns.

DEVELOPMENT OF PHOTOCATALYTIC SENSORS FOR REAL-TIME MONITORING OF AIR AND WATER QUALITY
Abstract
A photocatalytic sensor system for real-time air and water quality monitoring comprises a reaction chamber with a semiconductor-coated substrate activated by light, a sensing electrode array detecting reactive photochemical species, and a signal processing unit for pollutant-specific interpretation. The system integrates microfluidic architecture for controlled sample flow, a tunable illumination source for spectral selectivity, and a wireless transmission module for remote data visualization. Calibration elements allow periodic accuracy correction using standard pollutants. The arrangement enables continuous detection and classification of environmental contaminants.
, Claims:Claims
I/We Claim:
CLAIM 1.
A photocatalytic sensor system for real-time monitoring of air and water quality, comprising: a photocatalytic reaction chamber including a substrate layer coated with a semiconducting metal oxide; an ultraviolet or visible light illumination source positioned to irradiate said substrate layer to activate said semiconducting metal oxide; a fluid inlet configured to introduce an environmental sample comprising air or water into the photocatalytic reaction chamber; a sensing electrode arrangement positioned downstream of the substrate layer and configured to detect reactive species generated through photocatalytic reactions; and a signal processing unit operatively connected to the sensing electrode arrangement, said signal processing unit being configured to interpret electrical changes corresponding to variations in pollutant concentrations within the environmental sample.
CLAIM 2.
The photocatalytic sensor system as claimed in claim 1, wherein said semiconducting metal oxide comprises titanium dioxide doped with transition metals or rare earth elements to extend photocatalytic activity into the visible spectrum and enhance detection sensitivity for volatile organic compounds or dissolved chemical contaminants.
CLAIM 3.
The photocatalytic sensor system as claimed in claim 1, wherein said sensing electrode arrangement comprises an array of interdigitated electrodes coated with conductive polymer films, said arrangement being configured to detect transient oxidation or reduction products formed on the substrate layer due to photocatalytic decomposition of airborne or waterborne pollutants.
CLAIM 4.
The photocatalytic sensor system as claimed in claim 1, wherein said signal processing unit comprises a microcontroller interfaced with an analog-to-digital converter, said microcontroller being configured to implement digital filtering, baseline correction, and pollutant-specific threshold algorithms to enable real-time quantitative detection and classification of chemical species.
CLAIM 5.
The photocatalytic sensor system as claimed in claim 1, further comprising a data transmission module integrated with said signal processing unit, said module being configured to wirelessly transmit pollutant concentration data to a cloud-based dashboard via Wi-Fi, LoRa, or cellular network for remote visualization and archival.
CLAIM 6.
The photocatalytic sensor system as claimed in claim 1, wherein said reaction chamber comprises a microfluidic architecture having a serpentine or spiral flow path, said architecture being configured to prolong residence time of the environmental sample within the illuminated region, thereby increasing reaction efficiency and sensitivity.
CLAIM 7.
The photocatalytic sensor system as claimed in claim 1, wherein said substrate layer is a nanoporous glass, ceramic, or polymer membrane impregnated with the semiconducting metal oxide, said membrane being configured to facilitate high surface area interactions with the fluid sample while maintaining mechanical integrity and minimizing flow resistance.
CLAIM 8.
The photocatalytic sensor system as claimed in claim 1, further comprising a calibration module including a reservoir containing known concentrations of standard pollutants, a selector valve operatively coupled to said fluid inlet, and an algorithm within said signal processing unit to dynamically correct sensor drift and measurement variance by periodically introducing said standards.
CLAIM 9.
The photocatalytic sensor system as claimed in claim 1, wherein said illumination source includes a tunable wavelength emitter capable of selectively activating photocatalytic reactions at desired energy bands, thereby enabling selective detection of specific pollutants based on their photoreaction kinetics with the coated semiconducting surface.
CLAIM 10.
The photocatalytic sensor system as claimed in claim 1, wherein said signal processing unit is operatively configured to integrate machine learning models trained on pollutant-specific spectral response datasets, said models being configured to predict and classify types and concentrations of pollutants with increased confidence based on real-time sensor data patterns.