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Papers
61,005 resultsShowing papers similar to Optical parameter sensing: sensitivity limits and the advantages of using spatial modes of light
ClearCharacterization of a multilevel micro/nano-plastics Infrared Spectroscopy using optical chopper modulation and induced anti-stokes shift techniques
Researchers designed a new infrared spectroscopy system combining optical modulation and laser techniques to detect nanoplastics and microplastics smaller than 10 micrometers — well below the 20-micrometer detection limit of most current instruments — potentially enabling more sensitive identification of the tiniest plastic particles in environmental samples.
Direct Nanoparticle Sensing in Liquids with Free-Space Excited Optical Whispering-Gallery-Mode Microresonators
Despite its title referencing nanoparticle sensing, this paper studies an optical physics technique using laser-excited glass microspheres (whispering-gallery-mode resonators) to detect individual nanoparticles in liquid — not microplastic pollution specifically. It examines the physics of light resonance in micrometer-scale glass beads and is only tangentially relevant to nanoplastic detection as a general sensing technology.
Exploring the Ultralow Limit of Detection for Aromatic/Hydrophobic Nanoplastics with Ultrasmall Size Enables an LSPR Optical Microfiber
Researchers developed an advanced optical microfiber sensor capable of detecting nanoplastics at ultra-low concentrations, significantly surpassing the sensitivity of existing detection methods. The sensor uses localized surface plasmon resonance to identify aromatic and hydrophobic nanoplastic particles of extremely small sizes. The technology could enable early environmental monitoring of nanoplastic contamination in real-world water samples where current methods fall short.
Optical innovations in microplastic analysis: a critical review of detection strategies
This review surveys advances in optical methods for microplastic detection, including spectroscopic techniques, imaging systems, and sensor technologies. Researchers found that emerging approaches like surface-enhanced Raman spectroscopy combined with machine learning are enhancing automation and detection accuracy. The study identifies the need for standardized protocols and improved techniques to handle the challenges of detecting microplastics in complex environmental and biological samples.
On optical sensing of surface roughness of flat and curved microplastics in water
Researchers developed and tested an optical sensor prototype capable of detecting microplastic particles of different shapes and surface textures in water by measuring light reflection patterns. The sensor offers a potential path to faster, in-situ microplastic detection without requiring chemical analysis.
Detection of microplastic samples based on spatial heterodyne microscopic differential Raman spectroscopy
Researchers built a new optical instrument — spatial heterodyne microscopic differential Raman spectroscopy — specifically designed to identify microplastics more reliably than conventional detectors. The system achieved better signal-to-noise ratios for four common plastic types (PS, PC, PP, HDPE) and suppressed fluorescence interference, all without an expensive microscope. Better detection tools like this are essential for accurately measuring microplastic contamination in environmental samples.
Outlook on optical identification of micro- and nanoplastics in aquatic environments
Researchers studied the optical properties of micro- and nanoplastics and evaluated near-infrared spectroscopy as a detection method for plastic particles in water, finding that optical techniques show promise for rapid, non-destructive identification. Improved optical detection methods could enable faster and more cost-effective monitoring of plastic pollution in aquatic environments.
On the Potential for Optical Detection of Microplastics in the Ocean
This study examines the potential for optical methods to detect microplastics in ocean water at large spatial scales, noting that while optical detection is promising for overcoming the limitations of discrete water sampling, methods remain in early development and reference libraries of microplastic optical properties are sparse.
A prototype of a portable optical sensor for the detection of transparent and translucent microplastics in freshwater
Researchers developed a portable prototype optical sensor capable of detecting transparent and translucent microplastics in freshwater by simultaneously measuring specular laser light reflection and transmission, offering a feasibility pathway for field-deployable microplastic monitoring.
Advanced Optical Imaging Technologies for Microplastics Identification: Progress and Challenges
This review surveys advanced optical imaging technologies used to identify microplastics and nanoplastics in environmental samples. Researchers compared techniques like Raman spectroscopy, infrared imaging, and fluorescence microscopy, noting their strengths and limitations for detecting increasingly small particles. The study highlights that improving detection methods is essential for accurately monitoring the full scope of plastic pollution.
Detection of microplastics via a confocal-microscope spatial-heterodyne Raman spectrometer with echelle gratings
Researchers built a confocal microscope combined with an echelle-grating spatial-heterodyne Raman spectrometer for detecting microplastics with high sensitivity and resolution. The system achieved spectral resolution approaching 0.67 wavenumbers per centimeter and successfully identified different plastic polymer types. The study demonstrates an efficient and reliable optical detection method that could improve real-time monitoring of microplastic contamination.
Detection of microplastics and nanoplastics: Are Raman tweezers and enhanced Raman methods the solution for sub 20 μm particles?
Raman tweezers — devices that use a laser beam to trap and analyze individual particles — combined with plasmonic enhancement techniques can detect and characterize nanoplastics and microplastics smaller than 20 µm, a size range that defeats most conventional filtration-based detection methods. Improving detection sensitivity for the smallest plastic particles is critical because nanoplastics are thought to be the most biologically active fraction, capable of crossing cell membranes and accumulating in tissues.
Identification and visualisation of microplastics/ nanoplastics by Raman imaging (ii): Smaller than the diffraction limit of laser?
Researchers examined whether confocal Raman microscopy can identify and visualize nanoplastics smaller than the diffraction limit of the laser, analyzing the lateral intensity distribution of Raman signals from nanoplastics ranging from approximately 30 to 600 nm in diameter. The study found that while imaging resolution is limited by diffraction, chemical identification of sub-diffraction-limit nanoplastics remains possible.
Optofluidic light-droplet interaction for rapidly assessing the presence of plastic microspheres within aqueous suspensions
Scientists developed a new device that can quickly detect tiny plastic particles (called microplastics) in water by shining light through water droplets and measuring how much light gets blocked. The device can spot extremely small amounts of plastic pollution - even particles smaller than the width of a human hair. This technology could help us better monitor plastic contamination in drinking water and the environment, which is important since these tiny plastics can harm both ecosystems and human health.
Optimization of a hyperspectral imaging system for rapid detection of microplastics down to 100 µm
Researchers optimised a commercially available hyperspectral near-infrared imaging system with symmetrical converged-light lamps and macro-photography optics to enable rapid detection of microplastics down to 100 µm, substantially expanding the size range detectable by hyperspectral methods without requiring lengthy sample preparation.
Laser beam scattering for the detection of flat, curved, smooth, and rough microplastics in water
Researchers demonstrated that laser beam scattering using a low-cost prototype sensor can detect microplastic particles of varying shapes — flat, curved, smooth, and rough — in water, offering a potential foundation for affordable in-situ optical monitoring tools. The study advances understanding of light-microplastic interactions needed to design practical field detection systems.
Development and Analysis of Multifeature Approaches in SPR Sensor Development
This paper is not about microplastics; it develops surface plasmon resonance (SPR) optical fiber sensors for refractive index measurement, using machine learning to improve sensor accuracy.
A metal-insulator-metal waveguide-based plasmonic refractive index sensor for the detection of nanoplastics in water
Researchers designed a light-based sensor using a metal-insulator-metal waveguide and square-ring resonator that can detect nanoplastics in water at extremely low concentrations by measuring tiny changes in how light bends through the sample. The optimized sensor achieved a sensitivity of 2700 nm/RIU, making it a promising tool for detecting minute levels of plastic contamination in water.
High-resolution, broad-spectral-range Raman measurement using a spatial heterodyne spectrometer with separate filters and multi-gratings
Researchers developed a spatial heterodyne Raman spectrometer with separate filters and multiple gratings that achieves high spectral resolution over a broad range in a single measurement, and demonstrated it can identify microplastics even in the presence of fluorescence interference. Better analytical tools like this are critical for accurately characterizing the types and quantities of microplastics in environmental samples.
Detection of Microplastics in Water and Ice
Researchers explored optical detection methods for identifying microplastics floating on water surfaces or trapped in ice, taking advantage of the unique light-reflecting properties of different plastic types. Advances in optical detection are important for developing faster, non-destructive tools for monitoring microplastic pollution.
Miniaturization of Sensor Systems for Marine Environmental Measurement Based on Optofluidic Technology
This paper reviews advances in miniaturised optofluidic sensor systems for marine environmental monitoring, with applications to detecting pollutants including microplastics. It evaluates current technologies and highlights the potential of integrated optical and microfluidic platforms for in situ, low-cost ocean surveillance.
Direct Nanoplastics Detection Below the Diffraction Limit Using Micro Raman
Researchers demonstrated that micro-Raman spectroscopy can directly detect polystyrene nanoplastic particles as small as 20 nm — far below the normal diffraction limit. This advances analytical capabilities for detecting the smallest nanoplastic particles in environmental samples.
Analytical solution of the classical Rayleigh length definition, including truncation at arbitrary values
Despite its title referencing Rayleigh length definition, this paper studies the physics of focused laser beams in optical microscopy — not microplastic pollution. It examines mathematical models for predicting how tightly a laser can be focused at high numerical apertures and is not relevant to microplastics or human health.
Investigation of optical properties of microplastics
Researchers collected sand from Los Angeles beaches and studied the optical properties of naturally occurring microplastics using a laser-tweezer setup. The resulting database of optical characteristics is intended to help develop tools for detecting microplastics and studying their interactions with ocean microorganisms.