Variable Wavelength Research Articles

Tapping the Potential of Modulated Light to Ward off Pathogens

Antimicrobial resistance of pathogens poses a significant challenge to public health worldwide which necessitates urgent innovative approaches for infection control. The interplay between light and biological organisms has been a subject of interest for decades. In recent years, modulated light has gained attention as a potential tool for combating pathogens. This short paper appraises the possibility of using modulated light, specifically light with a controlled variation in intensity or wavelength, as a weapon against harmful microorganisms.

Direct comparison of different protocols to obtain surface enhanced Raman spectra of human serum

Label-free Surface Enhanced Raman Spectroscopy (SERS) is a rapid technique that has been extensively applied in clinical diagnosis and biomedicine for the analysis of biofluids. The purpose of this approach relies on the ability to detect specific “metabolic fingerprints” of complex biological samples, but the full potential of this technique in diagnostics is yet to be exploited, mainly because of the lack of common analytical protocols for sample preparation and analysis. Variation of experimental parameters, such as substrate type, laser wavelength and sample processing can greatly influence spectral patterns, making results from different research groups difficult to compare. This study aims at making a step toward a standardization of the protocols in the analysis of human serum samples with Ag nanoparticles, by directly comparing the SERS spectra obtained from five different methods in which parameters like laser power, nanoparticle concentration, incubation/deproteinization steps and type of substrate used vary. Two protocols are the most used in the literature, and the other three are “in-house” protocols proposed by our group; all of them are employed to analyze the same human serum sample. The experimental results show that all protocols yield spectra that share the same overall spectral pattern, conveying the same biochemical information, but they significantly differ in terms of overall spectral intensity, repeatability, and preparation steps of the sample. A Principal Component Analysis (PCA) was performed revealing that protocol 3 and protocol 1 have the least variability in the dataset, while protocol 2 and 4 are the least repeatable.

Fluctuations in the Photoluminescence Excitation Spectra of Individual Semiconductor Nanocrystals.

Most single quantum emitters display non-steady emission properties. Models that explain this effect have primarily relied on photoluminescence measurements that reveal variations in intensity, wavelength, and excited-state lifetime. While photoluminescence excitation spectroscopy could provide complementary information, existing experimental methods cannot collect spectra before individual emitters change in intensity (blink) or wavelength (spectrally diffuse). Here, we present an experimental approach that circumvents such issues, allowing the collection of excitation spectra from individual emitters. Using rapid modulation of the excitation wavelength, we collect and classify excitation spectra from individual CdSe/CdS/ZnS core/shell/shell quantum dots. The spectra, along with simultaneous time-correlated single-photon counting, reveal two separate emission-reduction mechanisms caused by charging and trapping, respectively. During bright emission periods, we also observe a correlation between emission red-shifts and the increased oscillator strength of higher excited states. Quantum-mechanical modeling indicates that diffusion of charges in the vicinity of an emitter polarizes the exciton and transfers the oscillator strength to higher-energy transitions.

The Uncertainty Assessment by the Monte Carlo Analysis of NDVI Measurements Based on Multispectral UAV Imagery.

This paper proposes a workflow to assess the uncertainty of the Normalized Difference Vegetation Index (NDVI), a critical index used in precision agriculture to determine plant health. From a metrological perspective, it is crucial to evaluate the quality of vegetation indices, which are usually obtained by processing multispectral images for measuring vegetation, soil, and environmental parameters. For this reason, it is important to assess how the NVDI measurement is affected by the camera characteristics, light environmental conditions, as well as atmospheric and seasonal/weather conditions. The proposed study investigates the impact of atmospheric conditions on solar irradiation and vegetation reflection captured by a multispectral UAV camera in the red and near-infrared bands and the variation of the nominal wavelengths of the camera in these bands. Specifically, the study examines the influence of atmospheric conditions in three scenarios: dry-clear, humid-hazy, and a combination of both. Furthermore, this investigation takes into account solar irradiance variability and the signal-to-noise ratio (SNR) of the camera. Through Monte Carlo simulations, a sensitivity analysis is carried out against each of the above-mentioned uncertainty sources and their combination. The obtained results demonstrate that the main contributors to the NVDI uncertainty are the atmospheric conditions, the nominal wavelength tolerance of the camera, and the variability of the NDVI values within the considered leaf conditions (dry and fresh).

Comparative Analysis of Effect of Culture Conditions on Growth and C-Phycocyanin Production in Helical and Linear Spirulina.

Spirulina (Arthrospira and Spirulina spp.) has always been characterized by the helical trichomes, despite the existence of linear forms. A great debate is now open on the morphological flexibility of Spirulina, but it seems that both trichome morphology and C-phycocyanin (C-PC) concentrations are influenced by the culture conditions.This work compared the effect of some key growth factors (medium pH as well as its carbon, potassium, and salt contents) on the growth and C-PC concentration of helical and linear Spirulina strains. Further, two-phase strategies, including light and nitrogen variation, were applied to increase the in vivo C-PC accumulation into the trichomes. Results showed that high pH induced trichomes elongation and improved growth but decreased C-PC content (+ 65 and + 43% vs. -83 and -49%, for helical and linear strains, respectively). Variations in carbon and salt concentrations negatively impacted growth and C-PC content, even if the linear strain was more robust against these fluctuations. It was also interesting to see that potassium increasing improved growth and C-PC content for both strains.The variation of light wavelength during the enrichment phase (in the two-phase strategy) improved by 50% C-PC accumulation in trichomes, especially after blue lighting for 96 h. Similar result was obtained after 48 h of nitrogen reduction, while its removal from the medium caused trichomes disintegration. The current work highlights the robustness of linear Spirulina strain and presents an efficient and scalable way to increase C-PC in vivo without affecting growth.

Fundamental spatial mode high power 808 nm double trench wide ridge waveguide laser

—Lasers operating at a wavelength of 808 nm, with watt-level output power and high beam quality in the fundamental spatial mode, have garnered significant attention due to their potential applications across various fields. Transverse optical confinement in double trench ridge waveguide lasers is determined by the width of the ridge and the refractive index difference between the ridge and trench. In this study, we have designed and fabricated a wide ridge laser operating at 808 nm with high power output and stable fundamental spatial mode based on this principle. The fundamental spatial mode operation was successfully achieved with an 8 μm ridge waveguide laser, producing an impressive output power of 1.3 W. The device exhibits a stable far-field as the current was increased from 0.3 A to 1.8 A. The laser's output power exhibits a 14% reduction with an increase in temperature of 80 °C, demonstrating a decrease rate of only 1.25 mW/°C and a wavelength variation rate of 0.22 nm/°C, indicating low sensitivity to temperature changes.

Assessment of the spectral misalignment effect (SMILE) on EarthCARE's Multi-Spectral Imager aerosol and cloud property retrievals

Abstract. The Multi-Spectral Imager (MSI) on board the Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) will provide horizontal information about aerosols and clouds. These measurements are needed to extend vertical cloud and aerosol property information, which is obtained from EarthCARE's active sensors, in order to obtain a full three-dimensional view of cloud and aerosol conditions. Mesoscale weather systems, in particular, will be characterized. The discovery of a non-compliance of the MSI visible–near-infrared–shortwave infrared (VNS) camera’s visible (VIS) and shortwave infrared (SWIR1) channels regarding a spectral central wavelength (CWVL) shift across-track of up to 14 nm (VIS) and 20 nm (SWIR1) led to the need for an analysis regarding its impact on MSI Level-2A aerosol and cloud products. A significant influence of the spectral misalignment effect (SMILE) on MSI retrievals is identified due to the spectral variation in gas absorption, surface reflectance, and aerosol and cloud properties within the spectral ranges of these MSI bands. For example, the VIS channel is positioned in close proximity to the red edge of green vegetation and is impacted by residual absorption of water vapor and ozone. Small central wavelength variations introduce uncertainties due to the rapid change in surface reflectance for conditions with low optical thickness. The present central wavelength shift in the VIS towards shorter wavelengths than at nadir introduces a relative error in transmission of up to 3.3 % due to the increasing influence of water vapor and ozone absorption. We found relative errors in the top-of-atmosphere (TOA) signal due to the SMILE of up to 30 % for low optical thickness over a land surface in that band. Since the magnitude of the impact strongly depends on the underlying surface and atmospheric conditions, we conclude that accounting for the SMILE in Level-2 retrievals or correcting the Level-1 signal will improve MSI aerosol and cloud product quality.

Therapy of Tooth Decay and Gingivitis Using a Multi-Wavelength Halogen Lamp

The effect of a halogen lamp with multiple wavelengths was studied on the shrinkage of the number and size of infected organ cells in the gum areas and carious holes in the teeth. Various tests were conducted using a halogen lamp (500 watts) for time periods ranging from (0.5 - 1) hour, intermittent and with variable wavelength, with control In the frequency and intensity of the light used. Tests were conducted on a group of 170 cases, and the results were 90% successful regarding the treatment of caries and molars. From the practical results, we find it possible to use the technique of reducing the number and size of affected organ cells to treat many different diseases. Toothache is still treated when necessary by extracting the tooth, but the side effects are serious and may lead to a stroke, especially if the person with the tooth suffers from atherosclerosis due to the connection of blood vessels between the nervous system, the face and the heart. Nerve removal as an alternative treatment for tooth extraction leads to almost the same complications as removing some of the vessels. As for molar fillings, as a third alternative, it is also dangerous, for reasons including that the filling contains a toxic substance in one form or another. As for our treatment, it is a fourth and successful alternative.

Hybrid Photonic Structures: Gallium Phosphide Nanowires Decorated with Carbon Dots for Enhanced Broadband Emission

AbstractCarbon dots (CDs) are promising nanostructures in the field of photonics owing to the ease of fabrication, tunable and efficient emission. Gallium phosphide (GaP) nanowires are known for high surface area, optical density, waveguiding, resonant optical properties but lacking the luminescence due to the indirect bandgap. Here, hybrid photonic structures – GaP nanowires decorated with the CDs are fabricated and studied. Feasible drop‐casting deposition technique allows fabrication of dense vertical structures exhibiting efficient photoluminescence. Deposition of the CDs over the nanowires does not affect their luminescent properties demonstrating tolerance of the approach toward the surface aggregation. Tuning of the emission spectrum is obtained via variation of the excitation wavelength and CDs’ synthesis protocol. The structures emitting throughout the visible range are obtained. Analysis of the photoluminescence of an individual structure demonstrates the most intense and fast recombination processes at the ends of a nanowire. It is shown that the luminescence of the CDs’ covering a nanowire acting as a Fabry–Perot cavity is enhanced up to a factor of 3 governed by the Purcell effect. The obtained results unveil a path for fabrication of novel photonic devices via decoration of optically dense nanowires with CDs for enhanced and directed broadband emission.

Parameter-based transfer learning for severity classification of atopic dermatitis using hyperspectral imaging.

Because atopic dermatitis (AD) is a chronic inflammatory skin condition that causes structural changes, there is a growing need for noninvasive research methods to evaluate this condition. Hyperspectral imaging (HSI) captures skin structure features by exploiting light wavelength variations in penetration depth. In this study, parameter-based transfer learning was deployed to classify the severity of AD using HSI. Therefore, we aimed to obtain an optimal combination of classification results from the four models after constructing different source- and target-domain datasets. We designated psoriasis, skin cancer, eczema, and AD datasets as the source datasets, and the set of images acquired via hyperspectral camera as the target dataset for wavelength-specific AD classification. We compared the severity classification performances of 96 combinations of sources, models, and targets. The highest classification performance of 83% was achieved when ResNet50 was trained on the augmented psoriasis dataset as the source, with the resulting parameters used to train the model on the target Near-infrared radiation (NIR) dataset. The second highest classification accuracy of 81% was achieved when ResNet50 was trained on the unaugmented psoriasis dataset as the source, with the resulting parameters used to train the model on the target R dataset. ResNet50 demonstrated potential as a generalized model for both the source and target data, also confirming that the psoriasis dataset is an effective training resource. The present study not only demonstrates the feasibility of the severity classification of AD based on hyperspectral images, but also showcases combinations and research scalability for domain exploration.

Standardization and validation of a high-efficiency liquid chromatography with a diode-array detector (HPLC-DAD) for voriconazole blood level determination.

A specialized service for antifungal blood level determination is not available in Colombia. This service is essential for the proper follow-up of antifungal therapies. To standardize and validate a simple, sensitive, and specific protocol based on high-performance liquid chromatography with a diode array detector for voriconazole blood level quantification. We used an Agilent HPLC™ series-1200 equipment with a UVdiode array detector with an analytical column Eclipse XDB-C18 and pre-column Eclipse- XDB-C18 (Agilent). We used voriconazole as the primary control and posaconazole as an internal control. We performed the validation following the Food and Drug Administration (FDA) recommendations. The best chromatographic conditions were: Column temperature of 25°C, UV variable wavelength detection at 256 nm for voriconazole and 261 nm for posaconazole (internal standard); 50 μl of injection volume, 0,8 ml/min volume flow, 10 minutes of run time, and mobile phase of acetonitrile:water (60:40). Finally, retention times were 3.13 for voriconazole and 5.16 minutes for posaconazole. Quantification range varied from 0.125 μg/ml to 16 μg/ml. The selectivity and chromatographic purity of the obtained signal, the detection limits, and the standardized quantification make this method an excellent tool for the therapeutic monitoring of patients treated with voriconazole.

CN stretches around 4.4 microns dominate the IR absorption spectra of cyano-polycyclic aromatic hydrocarbons

ABSTRACT Anharmonic quantum chemical computations reveal a strong, narrow (width = 0.075 $\mu$m) band in the 4.3–4.5 $\mu$m region of the absorption spectra of the cyano-substituted polycyclic aromatic hydrocarbons (CN-PAHs) cyanonaphthalene, cyanoanthracene, cyanophenanthrene, and cyanopyrene. This narrow window with intense IR lines implies that CN-PAHs of various shapes and sizes offer little variation in both wavelength and intensity in this region. Subsequently, this band can be used as a tracer for CN-PAHs. The distinct features making up the band are assigned to mixed vibrational states consisting of the CN stretch fundamental and various combination bands, including in-plane CH bends, CC skeletal bends, and CC skeletal breathing motions. The extraordinarily large intrinsic intensity of the fundamental CN stretch is redistributed to nearby states via anharmonic coupling, which is readily captured when using second order vibrational perturbation theory with resonance polyad matrices. This redistribution of intensity leads to a complex spectrum. The intense bands in this wavelength region may contribute to the baseline continuum and undulating macroscopic structure seen in recent JWST NIRSpec observations.

Simultaneous Rapid Detection of Multiple Physicochemical Properties of Jet Fuel Using Near-Infrared Spectroscopy.

Jet fuel is the primary fuel used in the aviation industry, and its quality has a direct impact on the safety and operational efficiency of aircraft. The accurate quantitative detection and analysis of various physicochemical property indicators are important for improving and ensuring the quality of jet fuel in the domestic market. This study used near-infrared (NIR) spectroscopy to establish a suitable model for the simultaneous and rapid detection of multiple physicochemical properties in jet fuel. Using more than 40 different sources of jet fuel, a rapid detection model was established by optimizing the spectral processing methods. The measurement models were separately built using the partial least-squares (PLS) and orthogonal PLS algorithms, and the model parameters were optimized. The results show that after the Savitzky-Golay second derivative preprocessing, the PLS model built using the feature spectra selected by the uninformative variable elimination wavelength algorithm achieved the best measurement performance. Compared with the PLS model without preprocessing, the range of the resulting accuracy improvement was at least 15.01%. Under the optimal model parameters, the calibration set regression coefficient (Rc2) of the 11 jet fuel property index models ranged from 0.9102 to 0.9763, with the root-mean-square error of calibration values up to 0.8468 °C (for flash points). The regression coefficient (Rp2) of the validation set ranged from 0.8239 to 0.9557, with the root-mean-square error of prediction values up to 1.1354 °C (for flash points). The ratios of prediction to deviation (RPD) values were all in the range of 1.9-3.0, indicating high accuracy and reliability of the model. The rapid NIR analysis method established in this study enables the simultaneous and rapid detection of multiple physicochemical properties of jet fuel, thereby providing effective technical support for ensuring the quality of jet fuel in the market.

Switchable and tunable dual-wavelength thulium-doped fiber laser based on the parallel filter of the all-fiber Sagnac interferometer embedded with an FBG and the Fabry-Perot filter

A switchable and tunable dual-wavelength thulium-doped fiber laser (ST-DW-TDFL) based on the parallel filter is proposed and experimentally demonstrated in this study. In the proposed ST-DW-TDFL, there are two independent branches to form the parallel filter. One branch uses an all-fiber Sagnac interferometer embedded with a fiber Bragg grating (FBG-FSI) as the wavelength selection element, and the other branch uses a Fabry-Perot (FP) filter as the wavelength selection element. By adjusting two optical attenuators to change the light power of two branches, single and dual-wavelength output can be achieved and switched. On the basis of achieving dual-wavelength output, independent and continuous tuning of two wavelengths can be achieved by heating the FBG and adjusting the FP filter. The tuning range of one wavelength is up to 5.84 nm, while the tuning range of the other wavelength is up to 99.86 nm. The maximum wavelength variation and power fluctuation are less than 0.03 nm and 0.5 dB at room temperature. And the experimental results show that the proposed ST-DW-TDFL has flexible wavelength switching and tuning capabilities and good wavelength and power stabilities.

High sensitive optical fiber SPR sensor for label-free detection of Staphylococcus aureus

Optical fiber bacterial sensors have attracted attention in many fields due to their unique advantages. However, it is still difficult to promote its practicality which is mainly subject to their low sensitivity, inferior stability, and reliability. This work reported here an optical fiber surface plasmon resonance (SPR) biosensor enhanced by gold nanoparticles (AuNPs)/Au film coupling for label-free detection the Staphylococcus aureus (S. aureus), while both the gold substrates were successfully biofunctionalized with goat anti-human immunoglobulin G (IgG) as the probe to capture and detect the bacteria. In the experiment, the refractive index（RI） sensitivity of the Multimode-Singlemode-Multimode optical fiber (MSMOF) coated with Au film was improved by 19 % after the AuNPs were homogeneously decorated on the Au film surface. To detect S. aureus by the sensor, the SPR wavelength variation in the transmission spectrum was recorded, and its limit of detection (LOD) was demonstrated experimentally to be about 50 CFU/mL and was obtained theoretically to be 1.18 CFU/mL during its concentration range of 50–108 CFU/mL. Also, it shows great linearity in the range of 102-108 CFU/mL and the sensor exhibits excellent specificity and stability. This kind of SPR-enhanced optical fiber biosensor is fully promising for its applications in biomedicine, food safety, pharmaceuticals, etc.

High enrichment and measurement of heterocyclic aromatic hydrocarbons from environmental waters with magnetic resorcinol-formaldehyde nanocomposites coupled with high performance liquid chromatography

Heterocyclic aromatic hydrocarbons are concerned pollutants with carcinogenic toxicity, which exist universally in various environmental matrices and have great harm to environmental and human health. In present work, magnetic resorcinol-formaldehyde composites (Fe3O4@SiO2@R–F) were fabricated via aldol condensation reaction under alkaline condition. The prepared magnetic materials were examined and analyzed with Fourier transform infrared spectroscopy and other related instruments. The Fe3O4@SiO2@R–F composites were utilized to develop an efficient magnetic solid phase extraction (MSPE) method for extracting six heteropolyclic aromatic hydrocarbons from environmental water samples including carbazole (CB), 7-methylquinoline (7-MQL), 9-methylcarbazole (9-MCB), dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The analytes were analyzed by high performance liquid chromatography-ultraviolet variable wavelength detector (HPLC-VWD). The main factors affecting MSPE were optimized. With the optimal parameters, 9-MCB and 4-MDBT have good linearity over the concentration range of 0.1–300 μg L−1, and 7-MQL, CB, DBT and 4,6-DMDBT have good linearity over the concentration range of 0.5–300 μg L−1. The limits of detection were over the concentration range of 0.012–0.031 μg L−1. This method was successfully employed to measure real waters, and the spiked recoveries ranged from 89.4% to 99.9%. The results confirmed that the developed method was reliable, robust and could be employed as a usefully alternate way for analyzing such pollutants in waters.

Performance investigation of elevated source EBG TFET based photosensor for near-infrared light sensing applications

In this manuscript, an elevated source TFET with extended back gate (ES-EBG-TFET) based photosensor is designed to offer improvement in optical performance for detecting incident light of narrow-spaced wavelengths (∼100 nm) and low luminous intensity (<0.9 W/cm2) in the near-infrared (IR) range. The proposed photosensor combines the advantages provided by both the elevated top gate and extended back gate in the sense of increasing the line tunneling region at the source-channel (S–C) interface, resulting to improvement in illumination current (ILight), threshold voltage (Vth) and average subthreshold swing (SSavg) under the light state. Furthermore, the inclusion of an L-shaped pocket around the source region helps to reduce the corner effects at S–C interface in the sub-threshold region, thereby improving the signal-to-noise ratio (SNR) of the proposed photosensor for on-chip applications. Due to improved optical generation in the photosensing gate, a high spectral sensitivity (Sn) of ∼54 is achieved for ES-EBG-TFET based photosensor because the variation in wavelength (λ) of incident light from 1050 to 750 nm shows a two order change in ILight (ID at Vgs = 0.2V under light state) from 3.1 × 10−15 A/μm to 1.72 × 10−13 A/μm, respectively. Since the elevated source provides a space to create larger illumination window above the channel region, a high optical generation rate is observed for the proposed photosensor under the incident light with low intensity (<0.9 W/cm2). The maximum value of SNR is observed to be 66.4 dB at a λ of 750 nm, while the quantum efficiency (ƞ) and responsivity (R) are reported to be 74% and 0.59 A/W, respectively, around λ of 1050 nm. Moreover, an optimum length of back-gate underlap with drain (LBGUD) is found to enhance the magnitude of SNR (at λ of 750 nm) and Sn (750–1050 nm) from 25.6 to 63.1 dB and 14 to 52.8, respectively when the photosensor is operated at the ambipolar state (Vgs = −0.6 V and Vds = 0.5 V). Finally, the photosensing parameters such as Sn and SNR are analyzed under the presence of acceptor and donor interface traps and it is found that there is insignificant degradation in the optical performance of the proposed photosensor.

Therapy of Tooth Decay and Gingivitis Using a Multi-Wavelength Halogen Lamp

The effect of a halogen lamp with multiple wavelengths was studied on the shrinkage of the number and size of infected organ cells in the gum areas and carious holes in the teeth. Various tests were conducted using a halogen lamp (500 watts) for time periods ranging from (0.5 - 1) hour, intermittent and with variable wavelength, with control In the frequency and intensity of the light used. Tests were conducted on a group of 170 cases, and the results were 90% successful regarding the treatment of caries and molars. From the practical results, we find it possible to use the technique of reducing the number and size of affected organ cells to treat many different diseases.

Quantifying the Light-Absorption Properties and Molecular Composition of Brown Carbon Aerosol from Sub-Saharan African Biomass Combustion.

Sub-Saharan Africa is a hotspot for biomass burning (BB)-derived carbonaceous aerosols, including light-absorbing organic (brown) carbon (BrC). However, the chemically complex nature of BrC in BB aerosols from this region is not fully understood. We generated smoke in a chamber through smoldering combustion of common sub-Saharan African biomass fuels (hardwoods, cow dung, savanna grass, and leaves). We quantified aethalometer-based, real-time light-absorption properties of BrC-containing organic-rich BB aerosols, accounting for variations in wavelength, fuel type, relative humidity, and photochemical aging conditions. In filter samples collected from the chamber and Botswana in the winter, we identified 182 BrC species, classified into lignin pyrolysis products, nitroaromatics, coumarins, stilbenes, and flavonoids. Using an extensive set of standards, we determined species-specific mass and emission factors. Our analysis revealed a linear relationship between the combined BrC species contribution to chamber-measured BB aerosol mass (0.4-14%) and the mass-absorption cross-section at 370 nm (0.2-2.2 m2 g-1). Hierarchical clustering resolved key molecular-level components from the BrC matrix, with photochemically aged emissions from leaf and cow-dung burning showing BrC fingerprints similar to those found in Botswana aerosols. These quantitative findings could potentially help refine climate model predictions, aid in source apportionment, and inform effective air quality management policies for human health and the global climate.

Development of the RP-HPLC Method for Simultaneous Determination and Quantification of Artemether and Lumefantrine in Fixed-Dose Combination Pharmaceutical Dosage Forms.

Developing countries face enormous challenges with substandard and falsified antimalarial drugs. One specific issue is the lack of a simple, cost-effective, and robust HPLC method to simultaneously determine and quantify the active pharmaceutical ingredients (APIs) in fixed-dose artemether-lumefantrine pharmaceutical dosage forms. The current study developed a novel, simple, sensitive, precise, accurate, and cost-effective RP-HPLC method for the simultaneous determination and quantification of artemether and lumefantrine in pharmaceutical dosage forms. The HPLC analysis was carried out on an Agilent 1260 Infinity Series HPLC system equipped with an ODS Intersil-C8 (150 × 4.6 mm) 5.0 µm column, by isocratic elution. The mobile phase composition consisted of acetonitrile and 0.05% orthophosphoric acid buffer of pH 3.5 in the ratio of 70 : 30 v/v. The analysis was performed at a 1 mL/min flow rate and a column temperature of 25°C. The total run time was 6 minutes. The detection was done with a variable wavelength detector (VWD) at an isosbestic point wavelength (λ) of 210 nm. The developed method was validated according to the ICH guidelines concerning system suitability, specificity, linearity, accuracy, precision, and robustness. The system suitability of the developed method revealed satisfactory theoretical plates and symmetry factors. The method proved to be specific, with no interference of mobile phase or excipients. The calibration plot exhibited linearity over the concentration range of 275-1925 μg/mL with R2 = 0.9992 for artemether and a range of 150-1050 μg/mL with R2 = 0.9985 for lumefantrine. The accuracy of the method, determined by the recovery study, was 99.79-100.16% for artemether and 99.04-99.50% for lumefantrine. The % RSD values for intraday precision were 0.175 and 0.203, while interday precision values were 0.340 and 0.554 for artemether and lumefantrine, respectively. The method demonstrated robustness when subjected to slight modifications in the flow rate, column temperature, and mobile phase composition. The developed analytical method proved satisfactory as per ICH guidelines and hence can be used for the determination and quantification of artemether and lumefantrine in bulk drug and pharmaceutical dosage forms.