Raman Spectroscopy Research Articles

Diagnostic accuracy of autofluorescence-Raman spectroscopy for surgical margin assessment during Mohs micrographic surgery of basal cell carcinoma.

Autofluorescence (AF) - Raman spectroscopy is a technology that can detect residual basal cell carcinoma (BCC) on the resection margin of fresh surgically excised tissue specimens. The technology does not require tissue fixation, staining, labelling, or sectioning, and provides quantitative diagnosis maps of the surgical margins in 30 minutes. To determine the accuracy of the AF-Raman instrument to detect incomplete excisions of BCC during Mohs micrographic surgery, using histology as reference standard. Skin layers from 130 patients undergoing Mohs surgery at the Nottingham University Hospitals NHS Trust (September 2022 to July 2023) were investigated with the AF-Raman instrument. The layers were measured fresh, immediately after excision. The AF-Raman results and the intra-operative assessment by Mohs surgeons were compared to a post-operative consensus-derived reference produced by three dermatopathologists. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated. The AF-Raman analysis was successfully completed for 125 out of the 130 layers. The AF-Raman analysis covered 91% of the specimen surface area on average, with the lowest being 87% for eyelid and the highest being 94% for forehead specimens. The AF-Raman instrument identified positive margins in 24 out of 36 BCC-positive cases, resulting in a 67% sensitivity (95% confidence intervals (CI): 49%-82%) and negative margins in 65 out of 89 BCC-negative cases, resulting in a 73% specificity (95% CI 63%-82%). Only one out of the 12 false negative cases was caused by misclassification by the AF-Raman algorithm. The other 11 false negatives cases were produced because no valid Raman signal was recorded at the location of the residual BCC due to either occlusion by blood or poor contact between tissue and cassette window. The intra-operative diagnosis by Mohs surgeons identified positive margins in 31 out of 36 BCC-positive cases, 86% sensitivity (95% CI: 70%-95%), and negative margins in 79 out of 89 BCC-negative cases, 89% specificity (95% CI: 81%-95%). This study shows that the AF-Raman instrument has potential for intra-operative microscopic assessment of surgical margins in surgery of BCC. Further improvements are required for tissue processing to ensure complete coverage of the surgical specimens. ClinicalTrials.gov ID NCT03482622.

Research on disease diagnosis based on teacher-student network and Raman spectroscopy.

Diabetic nephropathy is a serious complication of diabetes, and primary Sjögren's syndrome is a disease that poses a major threat to women's health. Therefore, studying these two diseases is of practical significance. In the field of spectral analysis, although common Raman spectral feature selection models can effectively extract features, they have the problem of changing the characteristics of the original data. The teacher-student network combined with Raman spectroscopy can perform feature selection while retaining the original features, and transfer the performance of the complex deep neural network structure to another lightweight network structure model. This study selects five flow learning models as the teacher network, builds a neural network as the student network, uses multi-layer perceptron for classification, and selects the optimal features based on the evaluation indicators accuracy, precision, recall, and F1-score. After five-fold cross-validation, the research results show that in the diagnosis of diabetic nephropathy, the optimal accuracy rate can reach 98.3%, which is 14.02% higher than the existing research; in the diagnosis of primary Sjögren's syndrome, the optimal accuracy rate can be reached 100%, which is 10.48% higher than the existing research. This study proved the feasibility of Raman spectroscopy combined with teacher-student network in the field of disease diagnosis by producing good experimental results in the diagnosis of diabetic nephropathy and primary Sjögren's syndrome.

Microwave synthesis of magnesium phosphate-rGO as an effective electrode for supercapacitor application

Abstract Transition metal phosphate based materials is being used for energy storage because of P–O covalent bond which facilitates more storage compared to other transition metals and this covalent bond enhanced the electrochemical performance for supercapacitor applications. Pure magnesium phosphate (Mg3(PO4)2) were synthesized via microwave synthesis as the composite varies with rGO (MgPO-XrGO) X=25,50,75,100mg. The prepared composite materials were examined employing XRD, Raman, FT-IR, SEM and XPS studies. Electrochemical studies (CV, EIS, GCD) of three electrode system for the prepared electrodes were performed using Biologic SP-150 with 2M (H2SO4) as electrolyte. From the XRD results, triclinic structured MgPO was confirmed (JCPDS card #35–0329) and rGO has enhanced the crystallinity of MgPO composite. From Raman analyses, the well graphitization nature of rGO in composite MgPO was identified and from XPS analysis chemical composition of the elements was analyzed. The FT-IR fundamental modes of vibrations of PO 4 3 − ${\text{PO}}_{4}^{3-}$ (γ 1,γ 3,γ 4) were obtained. The electrochemical analysis of the prepared material such as pure and composite materials showed better performance. The high specific capacitance was obtained for MgPO-50rGO because MgPO has high coordination with rGO. As Mg2+ oxidation state has high chemical reactivity compared to other earth metals and other advantage is P–O covalent bond that enhanced the performance of the electrode. By facilitating these advantages, rGO is included as composite to develop the electrode to favor the practical applications. By using the optimum level rGO composite with MgPO4-50rGO a better new candidate was successfully developed for supercapacitor applications. The fabricated MgPO-50rGO//Activate carbon full cell set up exhibited the specific capacitance 61 Fg−1 at 1 Ag−1, 21.7 Wh kg−1 energy density and 790.0 W kg−1 power densities and explored outstanding capacitive retention in 2 electrode full cell setup cyclic stability of 99.1 % over the 5000 cycles.

Self-modification of Defective TiO2 under Controlled H2/Ar Gas Environment and Dynamics of Photoinduced Oxygen Vacancies.

In recent years, defective TiO2 has caught considerable research attention because of its potential to overcome the limits of low visible light absorption and fast charge recombination present in pristine TiO2 photocatalysts. Among the different synthesis conditions for defective TiO2, ambient pressure hydrogenation with the addition of Ar as inert gas for safety purposes has been established as an easy to realize process. Whether the Ar gas might still influence the resulting photocatalytic properties and defective surface layer remains an open question. Here, we reveal that the gas flow ratio between H2 and Ar has a crucial impact on the defective structure as well as the photocatalyic activity of TiO2. In particular, transmission electron microscopy (TEM) in combination with electron energy loss spectroscopy (EELS) revealed a larger width of the defective surface layer when using a H2/Ar (50%-50%) gas mixture over pure H2. Here, a possible reason could be the increase in dynamic viscosity of the gas mixture when Ar is added. Additionally, photoinduced enhanced Raman spectroscopy (PIERS) is implemented as a complementary approach to investigate the dynamics of the defective structures under ambient conditions which cannot be effortlessly realized by vacuum techniques like TEM.

Honey induces changes in the molecular structure and microstructure of gluten in wheat-rye sourdoughs.

Chemical oxidizers and redox enzymes have traditionally been used to enhance the quality of baked goods. However, consumers now seek natural and clean-label ingredients, avoiding those with chemical-sounding names. Honey, a natural source of glucose oxidase (GOX), represents a promising alternative to purified enzymes for baking purposes. This study aimed to evaluate the effect of honey on the molecular structure and microstructure of gluten proteins in sourdough fermented by different lactic acid bacteria (LAB) strains. Four wheat-rye (1:1) sourdoughs were prepared, each supplemented with honey and inoculated with a different LAB strain. Additionally, two uninoculated doughs, one with honey (honey dough) and the other without (control dough), were prepared under identical conditions. Electronic paramagnetic resonance spectroscopy revealed the presence of hydrogen peroxide in honey solutions, indicating its role as an active source of GOX. Raman spectroscopy showed that honey addition altered the molecular structure of gluten by increasing the proportion of random coils at the expense of α-helix structures. This change is likely attributed to the competition between honey sugars and gluten proteins for water molecules in this system. Moreover, honey led to a decrease in the free sulfhydryl content of gluten compared to the control dough, suggesting an increase in disulfide crosslinking points. These enhanced protein-protein interactions were observed in scanning electron microscopy micrographs as a coarse gluten network composed of interconnected strands and fibrils. All LAB strains exhibited optimal acidification (pH < 4.3) in honey-supplemented sourdoughs, promoting the hydrolysis of gluten proteins into smaller fragments. Overall, honey-supplemented sourdoughs showed a gradual increase in the β-sheet content while decreasing the proportion of random coils over time. This trend suggests that the polypeptide fragments interacted through interchain hydrogen bonds, leading to a more ordered structure, which likely contributes to providing dough with good baking aptitude.

Alteration in the Raman spectra of characteristic rock‐forming silicate mixtures due to micrometeorite bombardment

AbstractInnovative techniques are required for the in situ investigation of the surfaces of planetary bodies when landings are planned. Raman spectroscopy turned out as an excellent tool for fast mineralogical analyses on space missions. Contribution from a photoluminescence signal is not unexpected and is likely to be even more pronounced on celestial surfaces with a dilute or absent atmosphere exposed to strong space weathering, for example, micrometeorite bombardment. Such signals were found, for example, in Raman analysis of the probes from sample‐return missions. While photoluminescence is generally considered as an accompanying undesired product in the Raman spectral measurement, our studies show that some analytical information can be derived from this signal, and even more, due to the specific correlation of luminescence intensity with space weathering products. Therefore, we investigate the Raman spectra alteration of characteristic rock‐forming mineral mixtures (olivine, pyroxene and plagioclase) by micrometeorite bombardment, which is simulated by nanosecond‐pulse laser irradiation. The changes in the minerals are strongly dependent on the composition and structure. They range from disappearing changes in the minerals with simple chemistry and structure to complete amorphization of minerals with relatively low melting enthalpy. With Raman spectroscopy, we found out that the photoluminescence signals show resonant or anti‐resonant changes to specific mineral phases and amorphization. Furthermore, ablation‐induced iron nanoparticles of minerals containing Fe are detectable by Raman spectroscopy due to their alteration into iron oxides. Trapped volatiles in the matrices are analysed due to the formation of the compounds containing them. This broad spectrum of results indicating specific change phenomena due to space weathering can be effectively used for in situ Raman analysis in planetary missions.

Reconfiguring the Optical Selection Rule in Ultramicrotome‐Crafted Vertically Aligned InSe Ribbons

AbstractDue to the high carrier mobility and direct bandgap character, indium selenide (InSe) exhibits great advantages for advanced optoelectronic applications. However, the unique optical section rule in InSe weakens the light‐matter interaction when the electric field of illuminated light is perpendicular to the c‐axis of planar InSe flake. To overcome this constraint, ultramicrotome technique is introduced to achieve vertically aligned InSe ribbons, aiming to reconfigure the optical paths for improved optical absorption and device performance. The well‐designed InSe ribbons are acquired with uniform morphology, showing an integrated structure free of cracks or fragments. First, the structural symmetry, crystal orientation, and optical anisotropy of InSe ribbon are carefully revealed by polarization‐dependent Raman spectrum, second harmonic generation (SHG), and photoluminescence measurements. Then, the back focal plane (BFP) imaging of photoluminescence distinguishes the in‐plane and out‐of‐plane dipole emission of InSe ribbons and planar InSe flakes, respectively. Notably, the ribbon exhibits new PL peaks with energy lower than the exciton peak of InSe at low temperature, which is attributed to Se vacancies. The work by introducing vertically aligned InSe nanoribbons provides a new strategy to manipulate the light‐matter interactions and defect engineering for novel optoelectronics, which can be also extended to other 2D semiconductors.

Operando Raman spectroscopy uncovers hydroxide and CO species enhance ethanol selectivity during pulsed CO2 electroreduction

Pulsed CO2 electroreduction (CO2RR) has recently emerged as a facile way to in situ tune the product selectivity, in particular toward ethanol, without re-designing the catalytic system. However, in-depth mechanistic understanding requires comprehensive operando time-resolved studies to identify the kinetics and dynamics of the electrocatalytic interface. Here, we track the adsorbates and the catalyst state of pre-reduced Cu2O nanocubes ( ~ 30 nm) during pulsed CO2RR using sub-second time-resolved operando Raman spectroscopy. By screening a variety of product-steering pulse length conditions, we unravel the critical role of co-adsorbed OH and CO on the Cu surface next to the oxidative formation of Cu-Oad or CuOx/(OH)y species, impacting the kinetics of CO adsorption and boosting the ethanol selectivity. However, a too low OHad coverage following the formation of bulk-like Cu2O induces a significant increase in the C1 selectivity, while a too high OHad coverage poisons the surface for C-C coupling. Thus, we unveil the importance of co-adsorbed OH on the alcohol formation under CO2RR conditions and thereby, pave the way for improved catalyst design and operating conditions.

Structural, vibrational and optical characterisations of Li2Ba3(P2O7)2:Cr3+ by solid-state reaction method

ABSTRACT Cr3+ doped Li2Ba3(P2O7)2 pyrophosphate nanopowder was successfully synthesised by solid-state reaction technique. The nanopowder was characterised by several techniques. X-ray diffraction analysis reveals orthorhombic crystal structureand average crystallite size values 34.21 and 28.41 nm are determined by Debye Scherrer’s formula and Williamson-Hall (W-H) method. The morphology displayed both SEM and HR-TEM images are irregular stone-like shapes. EDS analysis confirms the constituted elements. The SAED patterns of HR-TEM with well matched with XRD data. FT-IR and Raman spectra analysis confirmed incorporation of Cr3+ in the Li2Ba3(P2O7)2 pyrophosphate nanopowder. The EPR spectrum exhibited signal at g = 1.968 which is attributed to interaction between Cr3+ and Cr3+ exchange pair. The site symmetry of Cr3+ ions occupy a distorted octahedral. Photoluminescence spectrum exhibited bands correspond to ultraviolet, blue and green regions. The evaluated CCT of 6517 K indicates yellowish-green emission near cold light which reveals that the present prepared sample is useful for LEDs applications.

Isotactic-polypropylene (iPP) wettability modified by surface DBD plasma

Abstract In this paper, atmospheric pressure plasma of ambient air was generated by surface dielectric barrier discharge (SDBD) device for the purpose of modifying the surface of isotactic-polypropylene (iPP). The effect of SDBD treatment time on the chemical and physical properties of iPP was studied using various analytical techniques including water contact angle (WCA), attenuated total reflection (ATR), Raman spectroscopy, X-ray diffraction (XRD), and atomic force microscopy (AFM). The results indicate that the hydrophilicity and the C=O bonds of the treated iPP were improved as observed, respectively, through WCA and FTIR analysis. The crystal structure was evaluated by Raman spectroscopy and XRD. It was found that the iPP chain was under microscopic stress, which affects its crystallinity degree depending on the duration of the treatment. Furthermore, the AFM analysis revealed that the surface roughness was substantially modified.&amp;#xD;

Morphological effect on Core@shell AuAg nanoparticles for detecting p‐aminothiophenol dimerization by surface‐enhanced Raman spectroscopy

AbstractA series of non‐spherical metallic Au and bimetallic core@shell AuAg nanoparticles (NPs) have been synthesized for SERS improvements. The bimetallic core@shell AuAg NPs were obtained through a controlled overgrowth of an Ag shell onto the surface of two types of non‐spherical Au NPs, used as seeds, Au nanooctaheda (Au NOc) and Au nanotriangles (Au NTs). This Ag overgrowth was able to produce bimetallic core@shell structures such as nanocubes and nanopyramids, respectively. Transmission electron microscopy (TEM) was used to determine the particle size and particle morphology for metallic and bimetallic NPs, and energy‐dispersive X‐ray (EDX) elemental mapping analysis confirmed the core@shell structure of the bimetallic NPs. The plasmonic absorption bands exhibited for each nanosystem were observed by UV–vis spectroscopy. The concentration of Au and Ag in the bimetallic systems was determined by inductively coupled plasma mass spectrometry (ICP‐MS). After synthesis and characterization, p‐aminothiophenol (PATP) was used as a model analyte to investigate the surface‐enhanced Raman spectroscopy (SERS) capabilities of the synthesized metallic and bimetallic nanosystems. In PATP, a dimerization reaction to 4,4′‐dimercaptoazobenzene (DMAB) is produced when it is adsorbed onto the surface of certain noble metals. This SERS analysis was performed at 10−4 M of PATP and by using two different laser wavelengths (532 and 785 nm) in all cases. In this context, we were able to detect the dimerization reaction of PATP to DMAB only for the bimetallic structures and under the 532 nm laser line. Moreover, we have found that the dimerization capacity also depends on the nanoparticle morphology.

In vivo assessment of TiO2based wear nanoparticles in periprosthetic tissues.

A multimodal approach combining inductively coupled plasma mass spectrometry (ICP-MS), single-particle ICP-MS (spICP-MS), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) and Raman spectroscopy enabled a deeper insight into the balance between total titanium (Ti), the soluble titanium fraction and titanium dioxidebased particle fraction levels in periprosthetic tissues collected from patients undergoing revision surgery. Hydrofluoric acid usage in the sample digestion allowed for complete digestion of TiO2 particles, thus enabling accurate estimation of total Ti levels. The TiO2 fraction represents 38-94% of the titanium load in the six samples where particles were detected, and the fraction is present mainly in samples from patients with aseptically loosened total hip arthroplasty. Further attention was given to this fraction determining the elemental composition, particle count, particle size and modification of TiO2. The spICP-MS analysis confirmed the presence of the TiO2-derived (nano)particles (NPs) with a 39- to 187-nm median size and particle count up to 2.3 × 1011 particles per gram of tissue. On top of that, the SEM-EDS confirmed the presence of the TiO2 nanoparticles with 230-nm median size and an anatase crystal phasewas determined by Raman spectroscopy. This study presents a novel multimodal approach for TiO2 particle determination and characterization in tissue samples and is the first in vivo study of this character.

Analysis of COF-300 synthesis: probing degradation processes and 3D electron diffraction structure.

Although COF-300 is often used as an example to study the synthesis and structure of (3D) covalent organic frameworks (COFs), knowledge of the underlying synthetic processes is still fragmented. Here, an optimized synthetic procedure based on a combination of linker protection and modulation was applied. Using this approach, the influence of time and temperature on the synthesis of COF-300 was studied. Synthesis times that were too short produced materials with limited crystallinity and porosity, lacking the typical pore flexibility associated with COF-300. On the other hand, synthesis times that weretoo long could be characterized by loss of crystallinity and pore order by degradation of the tetrakis(4-aminophenyl)methane (TAM) linker used. The presence of the degradation product was confirmed by visual inspection, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). As TAM is by far the most popular linker for the synthesis of 3D COFs, this degradation process might be one of the reasons why the development of 3D COFs is still lagging compared with 2D COFs. However, COF crystals obtained via an optimized procedure could be structurally probed using 3D electron diffraction (3DED). The 3DED analysis resulted in a full structure determination of COF-300 at atomic resolution with satisfying data parameters. Comparison of our 3DED-derived structural model with previously reported single-crystal X-ray diffraction data for this material, as well as parameters derived from the Cambridge Structural Database, demonstrates the high accuracy of the 3DED method for structure determination. This validation might accelerate the exploitation of 3DED as a structure determination technique for COFs and other porous materials.

Reliable Lift‐Off Patterning of Graphene Dispersions for Humidity Sensors

AbstractDispersion‐based graphene materials are promising candidates for various sensing applications. They offer the advantage of relatively simple and fast deposition via spin‐coating, Langmuir–Blodgett deposition, or inkjet printing. Film uniformity and reproducibility remain challenging in all of these deposition methods. Here, a scalable structuring method is demonstrated, characterized, and successfully applied for graphene dispersions. The method is based on a standard lift‐off process, is simple to implement, and increases the film uniformity of graphene devices. It is also compatible with standard semiconductor manufacturing methods. Two different graphene dispersions are investigated via Raman spectroscopy and Atomic Force Microscopy and observe no degradation of the material properties by the structuring process. Furthermore, high uniformity of the structured patterns and homogeneous graphene flake distribution is achieved. Electrical characterizations show reproducible sheet resistance values correlating with material quantity and uniformity. Finally, repeatable humidity sensing is demonstrated with van der Pauw devices, with sensing limits of less than 1% relative humidity.

Origin of deactivation of aqueous Na–CO2 battery and mitigation for long-duration energy storage

The development of long-duration energy storage technology is crucial to facilitate the efficient utilization of renewable energy sources while mitigating carbon dioxide production. In this study, we investigate the deactivation and reactivation mechanisms of the aqueous Na–CO2 battery during extended cycling. We have designed the cathode to include non-precious intermetallic catalysts. As the cell undergoes repeated cycles, the voltage polarization during discharge progressively rises, eventually leading to the cell's deactivation and formation of decomposition products clogging the electrode surface. Results obtained from comprehensive characterization techniques, including conductive atomic force microscopy (cAFM), Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and inductively coupled plasma-mass spectrometry provide insight into the decomposition products. We also showcase an electrochemical approach for regeneration of these aqueous cells. Our findings, along with the insights we have gained, provide a path toward creating long-duration systems with self-healing properties.

Effect of graphene oxide loaded on TiO2-nanotube-modified Ti on inflammatory responses

Abstract Although a titanium matrix modified with titanium dioxide nanotube (TNT) arrays can have anti-inflammatory effects in vitro, these effects are limited. In this study, the TNT surface was modified by electrodepositing graphene oxide (GO) to enhance the anti-inflammatory effect of the material. Scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction were used to characterize each of these materials. Cell Counting Kit-8 (CCK-8) was used to determine the cell proliferation status. Enzyme-linked Immunosorbent Assay (ELISA), immunofluorescence staining, and RNA sequencing were used to assess the regulation of inflammation in each group. Raman spectroscopy confirmed that GO was successfully loaded onto the surface. The SEM, ELISA, fluorescence staining, and RNA sequencing results indicated that TNT-GO can effectively inhibit the inflammatory response and induce the M2 polarization of macrophages. TNT-GO can weaken the surface inflammatory responses of materials, suppress the secretion of pro-inflammatory factors, and promote the M2 polarization of macrophages. These advantageous properties render TNT-GO a promising material for dental implants.

Quantitative analysis model based on surface‐enhanced Raman spectroscopy of malachite green adsorbed on gold nanoparticles film substrates

AbstractIn order to investigate the adsorption process of malachite green (MG) on gold nanoparticles, a simple gold nanoparticles‐assembled film was prepared as a substrate of surface‐enhanced Raman spectroscopy (SERS), and it was soaked in MG solutions of different concentrations. The kinetic adsorption process was investigated by SERS method and density functional theoretical calculations. When saturated adsorption was achieved, the relationship between the characteristic SERS band signal intensity and the logarithm of solution concentration of MG was consistent with Temkin adsorption isotherm model, where the R2 value was greater than 0.995, and the linear range was 1 × 10−3–1 × 10−7 M. Finally, a SERS quantitative analysis model of the relationship between the adsorption properties of surface species and the bulk concentration was established. According to the electrostatic interaction and co‐adsorption, we proposed the surface adsorption configurations and adsorption process of MG on the nanostructured gold films.

Temperature effects on the structure of lead metasilicate glass, supercooled liquid, crystal, and liquid: Vibrational anharmonicity and configurational transformations analyzed by molecular dynamics and Raman scattering

Raman spectroscopy and Molecular Dynamics (MD) simulations were employed to explore in detail the effects of temperature on the four stages of the PbO∙SiO2 system: glass, supercooled liquid, crystalline phases, and liquid. The Qn distribution up to 1153 K and the wavenumber temperature coefficients derived from vibrational anharmonicity were determined from the Raman data, whereas the structural transformation reflected in changes in the Qn population distribution up to 2400 K was inferred from MD simulations. The results indicate that reversible configurational transformations occur only in the higher temperature ranges of the supercooled liquid and more notably in the liquid state. During these transformations, the increase in the Q0 and Q1 populations occurs at the expense of the Q3 and Q4 populations. On the other hand, only vibrational anharmonicity was observed in the glass and crystalline states.

Structural study of strontium-containing iron-phosphate glasses for radioactive waste vitrification

Iron-phosphate glasses are a wide group of materials with a wide range of applications. Among others, they are promising materials in toxic waste vitrification because of their high chemical durability and relatively low processing temperature and time. They are a novel group of glasses that are considered in the vitrification of radioactive waste, especially those that cannot be treated using conventional borosilicate ones. Since strontium isotopes are one of the main fission products present in the waste, the influence of Sr on the structural properties of the glasses is an important factor.Strontium-containing iron-phosphate glasses were subjected to structural studies using FT-IR and Raman spectroscopies. The obtained spectra were described, and appropriate band assignments were done. Based on the research conducted, the structural features of the phosphate network and their changes were determined.The results obtained showed that strontium in relatively low content up to 20 mol% acts as the glass network charge compensator and can stabilize the network. Above this threshold, SrO can be treated as a pure modifier, leading to gradual depolymerization. Thus, this point may be treated as the maximum waste loading for effective strontium immobilization.

Enhancing Sensitivity and Selectivity in Pesticide Detection: A Review of Cutting-Edge Techniques.

The primary goal of our review was to systematically explore and compare the state-of-the-art methodologies employed in the detection of pesticides, a critical component of global food safety initiatives. New approach methods in the fields of luminescent nanosensors, chromatography, terahertz spectroscopy, and Raman spectroscopy are discussed as precise, rapid, and versatile strategies for pesticide detection in food items and agroecological samples. Luminescent nanosensors emerge as powerful tools, noted for their portability and unparalleled sensitivity and real-time monitoring capabilities. Liquid and gas chromatography coupled to spectroscopic detectors, stalwarts in the analytical chemistry field, are lauded for their precision, wide applicability, and validation in diverse regulatory environments. Terahertz spectroscopy offers unique advantages such as noninvasive testing, profound penetration depth, and bulk sample handling. Meanwhile, Raman spectroscopy stands out with its nondestructive nature, its ability to detect even trace amounts of pesticides, and its minimal requirement for sample preparation. While acknowledging the maturity and robustness of these techniques, our review underscores the importance of persistent innovation. These methodologies' significance extends beyond their present functions, highlighting their adaptability to meet ever-evolving challenges. Environ Toxicol Chem 2024;00:1-17. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.