Microplastics (MPs) are a growing environmental concern, requiring effective methods for identification and quantification. This study develops and evaluates an application-oriented workflow combining near-infrared hyperspectral imaging (NIR-HSI) with a self-organizing map (SOM) and a percent-based expansion tolerance (PBET) for simultaneous microplastic mapping and semi-quantitative surface-coverage estimation. Spectral data were collected from MP fragments (PET, PE, PP, and PS; 1–5 mm) prepared from commercial household plastic source materials and experimentally distributed on sand surfaces at varying

Salivary cortisone correlates more closely with serum free cortisol than salivary cortisol itself, making it the most clinically informative non-invasive marker of adrenal status. Yet its trace endogenous concentration has, until now, largely confined accurate quantification to laboratory-based ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). UHPLC-MS/MS demands substantial sample volumes and labour intensive offline preparation. These barriers disproportionately exclude patients who cannot reliably provide the required volumes, including paediatric, elderly and xerostomic populations. Here we report, to our knowledge, the first ambient mass spectrometry method to deliver UHPLC-MS/MS-equivalent quantification of an endogenous steroid biomarker from healthy human saliva across the clinically relevant range. Paper-arrow mass spectrometry (PA-MS), an ambient ionisation technique within the paper spray family, unifies extraction, analyte enrichment and ionisation on a single disposable paper substrate. Cortisone is quantified from 4 μL of saliva, a 50-fold reduction relative to UHPLC-MS/MS, within 10 min. Validated to ICH M10 bioanalytical criteria, the method achieves an LOQ of 0.5 ng/mL, precision ≤8.4% RSD, accuracy 96 to 105%, linearity over 0.5 to 50 ng/mL, and negligible matrix effects. Cross-validation against UHPLC-MS/MS in 28 specimens showed excellent agreement (mean difference 4.17 ± 6.98%). Cortisone, unlike cortisol, was free of co-eluting isobaric interferences, making it well suited to chromatography-free ambient analysis. PA-MS opens a practical route to decentralised endocrine diagnostics for populations underserved by current laboratory-based methods.

Carbon dots (CDs) synthesized using the direct heating method were examined as potential sensitizers in dye-sensitized solar cells (DSSCs). The energy gap (Eg) of green, yellow, orange, and red emission CDs (G-, Y-, O-, and R-CDs) was modulated by varying the amount of concentrated sulfuric acid. Ultraviolet-visible (UV-Vis) spectroscopy was employed to ascertain the Eg of these CDs. R-CD synthesized with 1.35 mL (24.82 mmol) of concentrated sulfuric acid exhibited the lowest Eg of 2.07 eV. The Lowest Unoccupied Molecular Orbital (LUMO) and Highest Occupied Molecular Orbital (HOMO) of these synthesized CDs ranged from 2.98 to 3.14 eV and 5.05 to 5.60 eV, respectively. The TiO2 electrode was sensitized with R-CD under different conditions including varying time, temperature, and concentrations. The resulting DSSC exhibited an efficiency of 0.16

Cortisol plays a central role in maintaining physiological homeostasis, and both cortisol excess and deficiency are associated with life-threatening conditions. Accurate diagnosis, adequate treatment and monitoring of disorders of cortisol secretion are essential for good health, normal growth and development. Although commercially available lateral flow immunoassay (LFI) strips can be used to measure cortisol, they have limitations, especially low sensitivity and limited quantitative performance, inhibiting their use in clinical settings. Here, we present a novel LFI platform integrated with surface-enhanced Raman scattering (SERS), employing precisely size-controlled gold nanoparticle clusters functionalised with Raman reporter molecules to overcome these limitations. The approach achieves exceptional sensitivity, covering the relevant therapeutic range in humans, with a limit of detection (LOD) for cortisol of 0.014 pg mL-1, which is >500 times more sensitive than conventional LFI strips. The platform also showed high specificity for cortisol. The diagnostic potential was confirmed by testing with human saliva samples (n = 28), cross-validated with UPLC-MS/MS, showing excellent correlation (R2 = 0.9977). Bland-Altman analysis demonstrated strong agreement, with all samples falling within the 95% limits and yielding a mean bias of -3.5% ± 13.2% relative to UPLC-MS/MS. Given its sensitivity, specificity and simplicity, this LFI-SERS platform offers strong potential for clinical translation to enable convenient cortisol monitoring.

Utilization of silicate minerals fillers in latex offer dual function as a compatible filler and cheapener that economical way to reduce latex consumption. This research explores the effect of using Engineered Silicate Composite Dispersion (ESD 086) as fillers for nitrile latex-supported gloves, seeking to explore their properties while ensuring cost-effectiveness. The reinforcement effect of novel Engineered Carbonate Dispersion (ECD 011) for ESD 086 filled Carboxylated Nitrile Butadiene Rubber (XNBR/ESD 086) latex films has also been explored. XNBR latex films were compounded with three variants of ESD 086 at different loadings (in phr). From three variants of ESD 086 fillers, variant ESD 086A at 10 phr shows the highest tensile strength. As the ESD 086A filler loading increased up to 15 phr, the tensile strength decreased, indicating the ineffectiveness to be used at higher loading. The work was continued by exploring the use of novel ECD 011 to minimize the decrement effect. The 15 phr ESD 086 filled XNBR latex films (XNBR/ESD 086A-15) were subjected to a hybrid loading from 0 to 1.2 phr with 0.2 phr staggered increment together with the reduction of ECD 011:ZnO ratio in the XNBR latex compounds. Results show that at 0.6:0.6 phr of ECD 011:ZnO, the tensile strength of XNBR/ESD 086A-15 latex films increased and the elongation at break also improved. Using ESD 086A can reduce the usage of XNBR latex. Still, it can only be used up to 10 phr (optimum loading) and ECD 011 can maintain the physical properties and offer maximum cost-saving options for XNBR latex glove formulation at higher loading of ESD fillers. Overall, both engineered dispersions offer potential commercial benefits for the Nitrile gloves industry.

Abstract Background Paracetamol is the most consumed medicine globally. Its accessibility contributes to common overdose. Paracetamol overdose is responsible for > 50% of acute liver failure cases, making it the second most common reason for a liver transplant. Rapid quantitation of paracetamol is crucial to guide treatment of paracetamol overdose. Current tests require invasive sampling and relatively long turnaround times. Paper arrow-mass spectrometry (PA-MS) combines sample collection, extraction, separation, enrichment and ionisation onto a single paper strip, achieving rapid, accurate, cost-effective and eco-friendly analysis direct from raw human saliva. Methods To validate PA-MS against an established test, 17 healthy adults were recruited. Samples were collected before and at 15, 30, 60, 120 and 240 min after ingesting 1 g of paracetamol. Plasma measured with an established clinical test served as the reference standard to validate PA-MS with three biofluids—plasma, resting saliva (RS) and stimulated saliva (SS). Participants’ views of blood, RS and SS sampling procedures were assessed qualitatively. Cross-validation was assessed using Lin’s concordance correlation coefficients (CCC), Bland–Altman difference plots, and ratios of PA-MS to the reference standard test. Results PA-MS using stimulated saliva offers a reliable alternative to intravenous blood sampling. The CCC is 0.93, the mean difference with the reference test is − 0.14 mg/L, and the ratios compared to the reference test are 0.84–1.27 from correlated samples collected at 5 intervals over 4 h for each participant. Conclusions Paracetamol detection from SS with PA-MS provides a reliable result that can aid timely treatment decisions. Differences between paracetamol concentration in resting and stimulated saliva were also identified for the first time, highlighting the importance of standardising saliva collection methods in general. This study marks a major milestone towards rapid and convenient saliva analysis.

We critically evaluate the current status of portable mass spectrometry (pMS), particularly where this aligns with ambient ionization. Assessing the field of pMS can be quite subjective, especially in relation to the portable aspects of design, deployment, and operation. In this review, we discuss what it means to be portable and introduce a set of criteria by which pMS and ambient ionization sources can be assessed. Moreover, we consider the recent literature in terms of the most popular and significant advances in portable instrumentation for ambient ionization and miniature mass spectrometers. Finally, emerging trends and exciting future prospects are discussed and some recommendations are offered.

INTRODUCTION: A rapid test for the presence of cerebrospinal fluid (CSF) would be ideal in the management of postoperative fluid collections after spinal surgery. In order to ascertain the nature of the fluid the gold standard has been to send the fluid for gel electrophoresis which is time consuming and expensive in order to determine the presence or absence of beta-2 transferrin. METHODS: A cassette containing a lateral flow strip was used with two conjugates: a gold nanoshell-anti-TF antibody conjugate (conjugate 1) and a gold nanoshell-lectin conjugate (conjugate 2).After a sample is applied, a chromatographic sandwhich forms in two detection zones to yield a detectable dark line: Test line 1 (T1) where anti-TF antibodies are embedded form a sandwich reaction with analyte (TF) and with conjugate 1 and test line 2 (T2) where embedded serum glycoproteins react with conjugate 2. A control line with anti-mouse IgG antibody is embedded to form a reaction with conjugate 1. We availed the well-known hook effect as both T1 and T2 detection zone development was inhibited by the saturation of binding sites of the conjugates and embedded material. RESULTS: 18 clinical samples of either CSF or postoperative drain fluid (serum) were tested using a third generation LFI. There were 7 CSF samples and 11 serum samples and one with buffer only. The hook effect-based LFI successfully discriminated positive clinical CSF samples from negative samples in all cases. CONCLUSIONS: This novel hook effect-based LFI sensor offers a fast, highly accurate and easy to use POC test for CSF leak.

Breath analysis is an area of significant interest in medical research as it allows for non-invasive sampling with exceptional potential for disease monitoring and diagnosis. Volatile organic compounds (VOCs) found in breath can offer critical insight into a person’s lifestyle and/or disease/health state. To this end, the development of a rapid, sensitive, cost-effective and potentially portable method for the detection of key compounds in breath would mark a significant advancement. Herein we have designed, built and tested a novel reagent-less atmospheric pressure photoionisation (APPI) source, coupled with mass spectrometry (MS), utilising a bespoke bias electrode within a custom 3D printed sampling chamber for direct analysis of VOCs. Optimal APPI-MS conditions were identified including bias voltage, cone voltage and vaporisation temperature. Calibration curves were produced for ethanol, acetone, 2-butanone, ethyl acetate and eucalyptol, yielding R2 > 0.99 and limits of detection < 10 pg. As a pre-clinical proof of concept, this method was applied to bacterial headspace samples of Escherichia coli (EC), Pseudomonas aeruginosa (PSA) and Staphylococcus aureus (SA) collected in 1 L Tedlar bags. In particular, PSA and SA are commonly associated with lung infection in cystic fibrosis patients. The headspace samples were classified using principal component analysis with 86.9% of the total variance across the first three components and yielding 100% classification in a blind-sample study. All experiments conducted with the novel APPI arrangement were carried out directly in real-time with low-resolution MS, which opens up exciting possibilities in the future for on-site (e.g., in the clinic) analysis with a portable system.

Melon (Cucumis melo L.) is a popular fruit consumed around the world. It has significant economic value as a crop, export product, and source of essential nutrients. Thus, using high-quality, authentic seed varieties is the first step toward achieving impactful agricultural production. Unfortunately, distinguishing between seed varieties using only human perception can be difficult because of their similar traits. Thus, dishonest distributors may trade low-quality seeds for high-quality seeds. In this study, seeds from five Thai melon varieties, Singapore Thai melon (ST), Nan Thai melon (NT), Round Thai melon (RT), Striped Singapore Thai melon (SST), and Golden and Long Thai melon (GLT), were classified using a distinctive discrimination method that combines modified selforganizing maps (SOMs) with near-infrared (NIR) spectroscopy. The physical characteristics, morphology, and thermal behavior of the seeds were also examined through optical microscopy, scanning electron microscopy, and thermogravimetric analysis, respectively. Attenuated total reflection-Fourier transform infrared, and NIR spectroscopy revealed that different varieties of melon seeds possess significant variations in lignin content and carbohydrate composition. Seed samples from the five Thai melon varieties were further classified using a modified SOM map created with optimized scaling value, map size, and a number of iteration parameters. Binary classification with the One vs Rest strategy and multiclass classification was performed to verify the constructed classifier model. The supervised SOMs developed herein can achieve the multiclassification of seed types effectively and efficiently, with a high accuracy of 95.52 % for the training set and 91.59 % for the test set, which were significantly superior to those of well-established discrimination models.

Direct infusion ionization methods provide the highest throughput strategy for mass spectrometry (MS) analysis of low-volume samples. But the trade-off includes matrix effects, which can significantly reduce analytical performance. Herein, we present a novel chemical approach to tackle a special type of matrix effect, namely type II isobaric overlap. We focus on detailed investigation of a nanodroplet-based esterification chemistry for differentiating isotopologue [M + 2] signal due to unsaturated fatty acid (FA) from the monoisotopic signal from a saturated FA. The method developed involves the online fusion of nonthermal plasma with charged nanodroplets, enabling selective esterification of saturated FAs. We discovered that unsaturated FAs undergo spontaneous intramolecular reaction via a novel mechanism based on a carbocation intermediate to afford a protonated lactone moiety (resonance stabilized cyclic carbonium ion), whose mass is the same as the original protonated unsaturated FA. Therefore, the monoisotopic signal from any saturated FA can be selectively shifted away from the mass-to-charge position where the isobaric interference occurs to enable effective characterization by MS. The mechanism governing the spontaneous intramolecular reactions for unsaturated FAs was validated with DFT calculations, experimentation with standards, and isotope labeling. This novel insight achieved via the ultrafast plasma-nanodroplet reaction environment provides a potentially useful synthetic pathway to achieve catalyst-free lactone preparation. Analytically, we believe the performance of direct infusion MS can be greatly enhanced by combining our approach with prior sample enrichment steps for applications in biomedicine and food safety. Also, combination with portable mass spectrometers can improve the efficiency of field studies since front-end separation is not possible under such conditions. The fusion of nonthermal plasma with charged nanodroplets enables selective esterification of saturated fatty acids, which is utilized to overcome challenges associated with type II isobaric overlap in direct infusion mass spectrometry.

The interaction of matter when separated by a distance is a fundamental question, whether such interactions occur through instantaneous action at a distance or retarded interaction (principle of locality)? While the mainstream consensus favors the principle of locality, instantaneous action at a distance offers certain advantages. Previously, instantaneous action at a distance has been viewed as an appearance or representation from specific gauge choices of electromagnetic potentials (retarded). In this paper, we propose a novel approach that combines Weber’s electrodynamics with the concept of vacuum polarization to explore a new possible connection between the two viewpoints: instantaneous action at a distance and the locality principle. This new approach aligns with the observation of locality in signal/energy propagation while retaining the notion of instantaneous action at a distance.

BACKGROUND AND OBJECTIVES:Rapid detection of cerebrospinal fluid (CSF) leaks is vital for patient recovery after spinal surgery. However, distinguishing CSF-specific transferrin (TF) from serum TF using lateral flow immunoassays (LFI) is challenging due to their structural similarities. This study aims to develop a novel point-of-care diagnostic assay for precise CSF leak detection by quantifying total TF in both CSF and serum. METHODS:Capitalizing on the substantial 100-fold difference in TF concentrations between CSF and serum, we designed a diagnostic platform based on the well-known "hook effect" resulting from excessive analyte presence. Clinical samples from 37 patients were meticulously tested using the novel LFI sensor, alongside immunofixation as a reference standard. RESULTS:The hook effect-based LFI sensor exhibited outstanding performance, successfully discriminating positive clinical CSF samples from negative ones with remarkable statistical significance (positive vs negative t -test; P = 1.36E-05). This novel sensor achieved an impressive 100% sensitivity and 100% specificity in CSF leak detection, demonstrating its robust diagnostic capabilities. CONCLUSION:In conclusion, our study introduces a rapid, highly specific, and sensitive point-of-care test for CSF leak detection, harnessing the distinctive TF concentration profile in CSF compared with serum. This novel hook effect-based LFI sensor holds great promise for improving patient outcomes in the context of spinal surgery and postsurgical recovery. Its ease of use and reliability make it a valuable tool in clinical practice, ensuring timely and accurate CSF leak detection to enhance patient care.

Paracetamol overdose is a leading cause of acute liver failure that can prove fatal. Establishing paracetamol concentration accurately and quickly is critical. Current detection methods are invasive, time-consuming and/or expensive. Non-invasive, rapid and cost-effective techniques are urgently required. To address this challenge, a novel approach, called Paper-Arrow Mass Spectrometry (PA-MS) has been developed. This technique combines sample collection, extraction, enrichment, separation and ionisation onto a single paper strip, and the entire analysis process, from sample to result, can be carried out in less than 10 min requiring only 2 μL of raw human saliva. PA-MS achieved a LOQ of 185 ng mL-1, mean recovery of 107 ± 7%, mean accuracy of 11 ± 8% and precision ≤5% using four concentrations, and had excellent linearity (r2 = 0.9988) in the range of 0.2-200 μg mL-1 covering the treatment concentration range, surpassing the best-in-class methods currently available for paracetamol analysis. Furthermore, from a panel of human saliva samples, inter-individual variability was found to be <10% using this approach. This technique represents a promising tool for rapid and accurate emergency diagnosis.

Carbon dots (CDs) are renowned for their unique properties with numerous and growing applications in various fields and industries. Although several methods are available to prepare CDs, low conversion yield, tedious purification processes and poor color purity remain major drawbacks. To address these issues, a cooling stage for full protonation prior to direct heating has been developed. This innovative method produces high-color purity solid-state CDs with a conversion yield of up to 99.5% in less than 6 min. The CDs synthesized by this method exhibited a highly crystalline structure, as confirmed by HRTEM, Raman and XRD analyses. In addition, the emission profile of the CDs could be effectively tuned by reducing the amount of concentrated sulfuric acid, resulting in a shift of the emission from 484 to 650 nm. The high-color purity of the CDs is postulated to be due to the solvent cage effect. Overall, this study presents a simple, efficient and rapid method for the preparation of high-quality CDs with excellent color purity and crystallinity.

The detection of biogenic amines released from degraded meats is an effective method for evaluating meat freshness. However, existing traditional methods like titration are deemed tedious, while the use of sophisticated analytical instruments is not amenable to field testing. Herein, a cyanostilbene-based fluorescent array was rapidly fabricated using macroarray synthesis on a cellulose paper surface to detect amines liberated from spoiled beef, fish, and chicken. The fluorescence changes of immobilized molecules from the interaction with gaseous amines were used to monitor changes in freshness levels. Thanks to the high-throughput nature of macroarray synthesis, a set of highly responsive molecules such as pyridinium and dicyanovinyl moieties were quickly revealed. Importantly, this method offers flexibility in sensing applications including (1) sensing by individual sensor molecules, where the fluorescence response correlated well with established titration methods, and (2) collective sensing whereby chemometric analysis was used to provide a cutoff of freshness with 73-100% accuracy depending on meat types. Overall, this study paves the way for a robust and cost-effective tool for monitoring meat freshness.

Weedy rice is one of the most problematic weeds in rice-growing regions, particularly in Southeast Asia. Unlike other types of weeds, it is extremely difficult to distinguish weedy rice from cultivated rice directly from paddy seeds as they exhibit common morphological features. As such weed management can be a difficult, time-consuming, and inaccurate process that is often carried out manually. This study offers a novel classification approach based on an artificial neural network (ANN), utilizing self-organizing maps (SOMs), to directly discriminate weedy rice using the near-infrared (NIR) hyperspectral imaging (HSI) technique. The physical attributes, thermal behavior, and chemical profiles of the weedy and cultivated rice were thoroughly investigated by a range of analytical techniques, including optical microscopy, scanning electron microscopy, thermogravimetric analysis, and direct analysis in real-time mass spectrometry (DART-MS). For direct sample analysis by HSI, a global self-organizing map was generated with optimized parameters (scaling value and map size). The color indices (Red, Green, Blue values) of the sample image were defined to obtain a color ratio that can be used to classify unknown samples. The optimal threshold for classification was carefully determined using a receiver operating characteristic (ROC) curve. Performance metrics (sensitivity, specificity, precision, accuracy, and misclassification error) were used to evaluate the performance of the model. Classification accuracies of 98% (Weedy vs PL2) and 88% (Weedy vs RD49) were obtained with balanced sensitivity and specificity. The classification was assessed from the whole sample image, which was completely independent of the selected region of interest. As far as we know, this is the first instance where SOMs have been utilized to appraise seed quality by means of authentic HSI images.

Surface-enhanced Raman scattering (SERS) is a powerful technique for detecting trace amounts of analytes. However, the performance of SERS substrates depends on many variables including the enhancement factor, morphology, consistency, and interaction with target analytes. In this study, we investigated, for the first time, the use of electrospray deposition (ESD) combined with a novel ambient focusing DC ion funnel to deposit a high density of gold nanoparticles (AuNPs) to generate large-area, uniform substrates for highly sensitive SERS analysis. We found that the combination of ambient ion focusing with ESD facilitated high-density and intact deposition of non-spherical NPs. This also allowed us to take advantage of a polydisperse colloidal solution of AuNPs (consisting of nanospheres and nanorods), as confirmed by finite-difference time domain (FDTD) simulations. Our SERS substrate exhibited excellent capture capacity for model analyte molecules, namely 4-aminothiophenol (4-ATP) and Rhodamine 6G (R6G), with detection limits in the region of 10-11 M and a relative standard deviation of <6% over a large area (∼500 × 500 μm2). Additionally, we assessed the quantitative performance of our SERS substrate using the R6G probe molecule. The results demonstrated excellent linearity (R2 > 0.99) over a wide concentration range (10-4 M to 10-10 M) with a detection limit of 80 pM.

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Geosmin and 2-methylisoborneol (2-MIB) are amongst the most common earthy and musty taste and odour (T&O) compounds found in drinking water. With low odour threshold detection limits below 10 ng L −1 , and the complexity of raw water matrices, these two compounds provide a significant challenge for water companies globally. In this research, for the first time, a novel and fully automated micro-solid phase-extraction (μSPE) method coupled with gas chromatography (GC)–mass spectrometry (MS) has been developed for the detection of geosmin and 2-MIB for drinking water analysis. The new automated method described herein is environmentally friendly requiring low raw water sample volumes, of 25 mL, and only 50 μL of elution solvent. Our μSPE-GC–MS method exhibits excellent linearity for both compounds (R 2 > 0.999) and low limits of detection of 2.0 ng L −1 and 4.3 ng L −1 for geosmin and 2-MIB, respectively. The method showed excellent recovery rates (95.1–100.1%) and good precision (RSD < 7%) in raw sample matrices. Our approach is fully automated onto a robotic workstation which can be readily integrated into a laboratory workflow for routine water analysis. Furthermore, the method has excellent potential to be incorporated within a portable system for onsite analysis.