Brief Report - (2025) Volume 12, Issue 5
Received: 01-Sep-2025, Manuscript No. jlop-26-179062;
Editor assigned: 03-Sep-2025, Pre QC No. P-179062;
Reviewed: 17-Sep-2025, QC No. Q-179062;
Revised: 22-Sep-2025, Manuscript No. R-179062;
Published:
29-Sep-2025
, DOI: 10.37421/2469-410X. 2025.12.220
Citation: Jovanović, Katarina. ”Photonic Sensors: Revolutionizing Environmental Monitoring.” J Laser Opt Photonics 12 (2025):220.
Copyright: © 2025 Jovanović K. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.
Photonic sensors are emerging as a transformative technology in environmental monitoring, offering unparalleled sensitivity and real-time data acquisition capabilities across a spectrum of applications. Their ability to detect minute changes in optical properties makes them ideal for identifying and quantifying various environmental contaminants. This field is rapidly advancing, driven by innovations in material science and nanotechnology, which are enabling the development of smaller, more efficient, and more versatile sensing devices. The following sections delve into specific examples of these advancements and their direct impact on environmental surveillance and protection. One significant area of development involves fiber optic sensors, which are being utilized for their robustness and ability to transmit optical signals over long distances. These sensors are particularly adept at detecting a wide range of pollutants, including heavy metals, volatile organic compounds, and greenhouse gases. The integration of advanced materials and nanostructures further enhances their performance, allowing for remote and in-situ environmental assessments that were previously unattainable. [1] Fiber Bragg gratings (FBGs) represent a specific type of fiber optic sensor that has shown great promise for gas detection. A notable application is the development of FBG-based sensors for the detection of ammonia gas. By coating the FBG with a sensitive material that alters its refractive index in the presence of ammonia, changes in the Bragg wavelength can be precisely measured, indicating the concentration of the gas. This technology is particularly relevant for monitoring in agricultural and industrial environments where ammonia levels can be critical. [2] The fusion of microfluidics with photonic sensing platforms is another frontier in environmental analysis. Microfluidic systems provide exquisite control over sample handling and reaction kinetics, significantly improving the performance of photonic sensors. For instance, microfluidic chips integrated with surface plasmon resonance (SPR) sensors have demonstrated enhanced sensitivity and speed in detecting heavy metal ions in water samples, offering a more efficient method for water quality assessment. [3] Optical fiber interferometers are also being explored for their utility in monitoring airborne particulate matter. These sensors operate by detecting shifts in interference patterns caused by the presence of particles, which alter the refractive index of the sensing medium. The non-intrusive nature and high sensitivity of interferometric techniques make them suitable for real-time air quality monitoring, even in challenging environmental conditions. [4] Nanomaterials are integral to the advancement of modern photonic sensors, playing a pivotal role in boosting their performance metrics. Materials such as quantum dots and plasmonic nanoparticles are being incorporated to create sensors with exceptional sensitivity and selectivity for environmental pollutants. The synergistic interaction between these nanomaterials and optical detection mechanisms is paving the way for the next generation of sophisticated environmental monitoring systems. [5] For the detection of volatile organic compounds (VOCs), photonic crystal fibers (PCFs) offer a unique platform. By functionalizing the PCF with specific polymer layers, sensors can be created that exhibit high sensitivity and rapid response times to VOCs. The principle of operation involves monitoring changes in the fiber's transmission spectrum as VOCs are adsorbed, making these sensors valuable for indoor air quality assessment and other applications requiring precise VOC detection. [6] Beyond single-point detection, distributed fiber optic sensing technology enables large-scale environmental monitoring. This technique allows for the assessment of conditions along the entire length of a fiber optic cable, providing spatial information on parameters like temperature, strain, and the presence of chemicals. It is particularly useful for monitoring the integrity of pipelines and detecting soil contamination over extensive areas. [7] Surface-enhanced Raman spectroscopy (SERS), when coupled with plasmonic nanostructures, provides a powerful method for trace-level detection of environmental contaminants. Research utilizing gold nanoparticles as SERS substrates has shown remarkable success in detecting pesticide residues in food and water. The high sensitivity and specificity of SERS offer significant advantages for food safety and broader environmental protection efforts. [8] Laser-induced fluorescence (LIF) is another photonic technique with considerable potential, particularly for the remote sensing of oil spills in marine environments. LIF leverages the distinct fluorescence signatures of various oil types to identify and quantify contamination. Its non-contact nature and high sensitivity are crucial for effective and timely response to marine pollution incidents. [9] Finally, the development of miniaturized and portable photonic sensors is critical for enabling on-site environmental analysis. Spectroscopic sensor systems utilizing light-emitting diodes (LEDs) and photodiodes have been developed for monitoring water quality parameters such as turbidity and pH. The low cost and portability of these systems promote widespread adoption in distributed water monitoring networks, facilitating more comprehensive and accessible water resource management. [10]
The landscape of environmental monitoring is undergoing a significant transformation, largely driven by the advancements in photonic sensor technology. These sensors are characterized by their high sensitivity, selectivity, and capacity for real-time data acquisition, making them indispensable tools for detecting a wide array of environmental pollutants. The articles reviewed here showcase diverse photonic sensing modalities, including fiber optic sensors, surface plasmon resonance (SPR) sensors, and interferometric sensors, each tailored for specific detection tasks such as identifying heavy metals, volatile organic compounds, and greenhouse gases. The progress in material science and nanotechnology is central to these developments, enabling the miniaturization and enhanced performance of these sensing devices, thereby facilitating remote and in-situ environmental assessments. [1] Among the various fiber optic sensing approaches, Fiber Bragg Gratings (FBGs) have emerged as a compelling technology for gas detection. A prime example is the development of an FBG-based sensor specifically designed for the detection of ammonia gas. This sensor functions by utilizing a sensing material coated onto the FBG, which alters the grating's refractive index in the presence of ammonia. This change leads to a measurable shift in the Bragg wavelength, providing a direct indication of ammonia concentration. The sensor demonstrates good sensitivity and selectivity, positioning it as a viable solution for continuous ammonia monitoring in critical agricultural and industrial settings. [2] The convergence of microfluidics and photonic sensing platforms represents a significant leap forward in chemical and biological analysis. Microfluidic devices offer precise control over sample manipulation and reaction conditions, which greatly amplifies the effectiveness of integrated photonic sensors. Specifically, the integration of microfluidic chips with Surface Plasmon Resonance (SPR) sensors has led to a marked improvement in the detection of heavy metal ions in water. This synergy optimizes sample delivery and reaction kinetics, resulting in lower detection limits and significantly faster analysis times for water quality assessment. [3] Optical fiber interferometers are another class of photonic sensors being actively developed for environmental applications, particularly for the detection of airborne particulate matter. These sensors leverage the interference patterns generated by light, which are modulated by the presence of particles. The sensitivity of the sensor to changes in the refractive index caused by these particles is key to its performance. The study highlights the potential of interferometric techniques for non-intrusive, real-time monitoring of air quality, offering robust solutions for challenging environments. [4] Nanomaterials are playing an increasingly critical role in elevating the capabilities of photonic sensors for environmental applications. The integration of various nanomaterials, such as quantum dots and plasmonic nanoparticles, is instrumental in the design of highly sensitive and selective sensors for detecting environmental pollutants. These nanomaterials enhance the interaction between the analyte and the optical detection mechanism, leading to improved performance and opening doors for the development of next-generation environmental monitoring systems that are both more effective and more efficient. [5] For the specific challenge of detecting Volatile Organic Compounds (VOCs), photonic crystal fibers (PCFs) offer a promising avenue. Researchers have developed PCF-based sensors functionalized with specialized polymer layers that exhibit high sensitivity and fast response times to VOCs. The operational principle relies on monitoring spectral changes within the PCF as VOC molecules interact with the functionalized surface. This approach makes the sensors well-suited for applications such as monitoring indoor air quality and other scenarios requiring precise VOC detection. [6] In the realm of large-scale environmental monitoring, distributed fiber optic sensing systems provide a powerful capability for continuous surveillance over extensive areas. This technology allows for the assessment of environmental conditions, such as temperature, strain, and chemical presence, along the entire length of an installed fiber optic cable by analyzing backscattered light signals. Its advantages are particularly evident in applications like pipeline integrity monitoring and the detection of soil contamination, offering a comprehensive solution for long-range environmental surveillance. [7] Surface-Enhanced Raman Spectroscopy (SERS), when combined with advanced plasmonic nanostructures, presents a highly effective method for the trace-level detection of environmental contaminants. This research showcases the development of SERS substrates employing gold nanoparticles for the detection of pesticide residues in food and water. The inherent high sensitivity and specificity of the SERS technique underscore its significant utility in ensuring food safety and contributing to broader environmental protection initiatives. [8] Laser-Induced Fluorescence (LIF) is a photonic technique that has demonstrated considerable promise for the remote sensing of oil spills in marine environments. The LIF method capitalizes on the characteristic fluorescence spectra emitted by different types of oil when excited by a laser. This allows for the identification and quantification of oil contamination. The techniqueâ??s non-contact nature and high sensitivity are crucial advantages for effective and rapid marine pollution monitoring. [9] Lastly, the drive towards on-site environmental analysis has spurred the development of compact and portable photonic sensor systems. This research highlights a spectroscopic sensor system utilizing light-emitting diodes (LEDs) and photodiodes, designed for the real-time measurement of key water quality parameters like turbidity and pH. The affordability and portability of this system make it an attractive option for widespread deployment in distributed water monitoring networks, thereby enhancing our ability to manage water resources effectively. [10]
Photonic sensors are revolutionizing environmental monitoring with their high sensitivity and real-time data capabilities. Various types of photonic sensors are being developed and applied for detecting pollutants such as heavy metals, volatile organic compounds, and particulate matter. These include fiber optic sensors, Fiber Bragg gratings (FBGs), microfluidic-integrated SPR sensors, optical fiber interferometers, photonic crystal fibers (PCFs), and distributed fiber optic sensing systems. Nanomaterials are enhancing sensor performance, enabling miniaturization and improved detection limits. Techniques like Surface-Enhanced Raman Spectroscopy (SERS) and Laser-Induced Fluorescence (LIF) offer trace-level detection and remote sensing capabilities for contaminants like pesticides and oil spills. Compact and portable spectroscopic sensors based on LEDs and photodiodes are also being developed for on-site water quality monitoring. These advancements collectively contribute to more effective and comprehensive environmental assessment and protection.
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Journal of Lasers, Optics & Photonics received 279 citations as per Google Scholar report
