High Reproducibility Research Articles

Bottom-up Histone Post-translational Modification Analysis using Liquid Chromatography, Trapped Ion Mobility Spectrometry, and Tandem Mass Spectrometry.

The amino acid position within a histone sequence and the chemical nature of post-translational modifications (PTMs) are essential for elucidating the "Histone Code". Previous work has shown that PTMs induce specific biological responses and are good candidates as biomarkers for diagnostics. Here, we evaluate the analytical advantages of trapped ion mobility (TIMS) with parallel accumulation-serial fragmentation (PASEF) and tandem mass spectrometry (MS/MS) for bottom-up proteomics of model cancer cells. The study also considered the use of nanoliquid chromatography (LC) and traditional methods: LC-TIMS-PASEF-ToF MS/MS vs nLC-TIMS-PASEF-ToF MS/MS vs nLC-MS/MS. The addition of TIMS and PASEF-MS/MS increased the number of detected peptides due to the added separation dimension. All three methods showed high reproducibility and low RSD in the MS domain (<5 ppm). While the LC, nLC and TIMS separations showed small RSD across samples, the accurate mobility (1/K0) measurements (<0.6% RSD) increased the confidence of peptide assignments. Trends were observed in the retention time and mobility concerning the number and type of PTMs (e.g., ac, me1-3) and their corresponding unmodified, propionylated peptide that aided in peptide assignment. Mobility separation permitted the annotation of coeluting structural and positional isomers and compared with nLC-MS/MS showed several advantages due to reduced chemical noise.

Evaluation of Psychometric Proprieties of Mann Assessment of Swallowing Ability (MASA) in Italian Language: A Cross-Sectional Study.

The aim of this cross-sectional study was to translate, culturally adapt, and evaluate the psychometric properties of the Italian version of the Mann Assessment of Swallowing Ability (MASA) in post-stroke individuals. The original MASA scale was translated and culturally adapted from English to Italian following the international guidelines. The internal consistency and test-retest reliability of the MASA-IT were assessed, and its concurrent validity was examined through Pearson correlation coefficients with the Italian versions of two established gold standard scales for dysphagia assessment: the Dysphagia Outcome Severity Scale (DOSS) and the De Pippo Test-Three Oz Water Swallow. The MASA-IT was administered to 78 participants. The items demonstrated excellent internal consistency, with Cronbach's alpha ranging between 0.86 and 0.89. The interclass correlation coefficient was 0.98 for inter-rater reliability and 0.99 for intra-rater reliability, indicating high reproducibility. Regarding concurrent validity, the MASA-IT showed a strong direct correlation with the DOSS scale (r = 0.949, p = 0.01) and an inverse correlation with the De Pippo Test (r = -0.783, p = 0.01), confirming its good concurrent validity. The Italian version of the Mann Assessment of Swallowing Ability (MASA-IT) is a reliable and valid tool for assessing swallowing ability in post-stroke patients. Its strong psychometric properties make it well suited for clinical use in Italy.

Intraindividual variability of semen quality, proteome, and sncRNA profiles in a healthy cohort of young adults.

Within-subject variability of semen parameters and molecular components of ejaculates in young men remains poorly understood. To investigate intraindividual variability (IIV) of semen parameters and molecular markers in repeated ejaculates from young men. Semen parameters were assessed in samples collected 6-8 days apart from 164 18-19-year old participants of the Russian Children's Study, a prospective cohort. Subsets of paired samples were used for label-free quantitation and targeted mass-spectrometry of proteins in seminal plasma (SP) and seminal extracellular vesicles (EVs), and for small non-coding RNA (sncRNA) profiling in EVs and spermatozoa using RNA-seq. The mean difference between two ejaculates, within-subject variation, intraclass correlation, and concordance correlation were used to assess IIV for all parameters. Low variability with high reproducibility and high reliability was considered if CVw<15% and ICC>0.90, respectively. Analytical variability was low for all investigated parameters in technical replicates. IIV was assessed for basic semen parameters and proteins in SPs and EVs: 319 and 777 proteins, respectively, using untargeted analysis; 9 and 10 proteins using targeted quantification. We also described the IIV for sncRNA, including microRNA, piwi-interacting RNA, tRNA, and tRNA-derived small RNA (tsRNA) in EVs (409 sncRNA and 78 tsRNA) and in spermatozoa (265 sncRNA and 15 tsRNA). We identified 22 and 27 non-overlapping proteins in SP and EVs, respectively, and 46 and 9 sncRNA, including 5 and 0 tsRNA in seminal EVs and spermatozoa, respectively, with low variability. The fatty acid synthase (FAS) had the lowest IIV in both media in targeted protein quantification. We identified a number of proteins and sncRNA with low variability among 111 proteins, 176 sncRNA, and 12 tsRNA which were previously suggested as biomarkers of male fertility and reproductive outcomes: lactotransferrin, cysteine-rich secretory protein 3, alpha-1-antichymotrypsin, epididymal sperm-binding protein 1, glutathione S-transferase Mu 3, alpha-1-acid glycoprotein 2, serum amyloid P-component, aminopeptidase N, neprilysin, FAS, and miR-10b-3p, miR-122-5p, miR-205-5p, miR-222-3p, miR-34c-5p, miR-509-3-5p, miR-888-5p, miR-892a, miR-363-3p, miR-941, miR-146a-5p, miR-744-5p. These molecules have low IIV and may be promising candidate biomarkers of male fertility and reproductive health.

Sample-Specific MS/MS Methods in High-Throughput Mass Spectrometry.

The drug discovery process increasingly relies on high-throughput sample analysis to accelerate the identification of viable drug candidates. Recently, chromatographic-free high-throughput mass spectrometry (HT-MS) technologies have emerged, significantly increasing sample readout speed and enabling the analysis of large sample sets. These HT-MS platforms continuously acquire data from various samples into a single data file, presenting challenges in applying distinctive data acquisition methods to specific samples. This study introduces a novel approach that integrates real-time sample loading status to activate sample-specific MS/MS data acquisition methods on the high-throughput acoustic ejection mass spectrometry platform. Effective method switching and high signal reproducibility were demonstrated across different data acquisition window durations in multiple reaction monitoring (MRM), high-resolution MRM (MRMHR), and information-dependent acquisition modes. This advancement provides a user-friendly and robust solution to the method-setting challenges of HT-MS, expanding the implementation of HT-MS platforms in drug discovery and other high-throughput analytical applications.

A low-cost dpMIG-seq method for elucidating complex inheritance in polysomic crops: a case study in tetraploid blueberry.

Next-generation sequencing (NGS) library construction often requires high-quality DNA extraction, precise adjustment of DNA concentration, and restriction enzyme digestion to reduce genome complexity, which results in increased time and cost in sample preparation and processing. To address these challenges, a PCR-based method for rapid NGS library preparation, named dpMIG-seq, has been developed and proven effective for high-throughput genotyping. However, the application of dpMIG-seq has been limited to diploid and polyploid species with disomic inheritance. In this study, we obtained genome-wide single nucleotide polymorphism (SNP) markers for tetraploid blueberry to evaluate genotyping and downstream analysis outcomes. Comparison of genotyping qualities inferred across samples with different DNA concentrations and multiple bioinformatics approaches revealed high accuracy and reproducibility of dpMIG-seq-based genotyping, with Pearson's correlation coefficients between replicates in the range of 0.91 to 0.98. Furthermore, we demonstrated that dpMIG-seq enables accurate genotyping of samples with low DNA concentrations. Subsequently, we applied dpMIG-seq to a tetraploid F1 population to examine the inheritance probability of parental alleles. Pairing configuration analysis supported the random meiotic pairing of homologous chromosomes on a genome-wide level. On the other hand, preferential pairing was observed on chr-11, suggesting that there may be an exception to the random pairing. Genotypic data suggested quadrivalent formation within the population, although the frequency of quadrivalent formation varied by chromosome and cultivar. Collectively, the results confirmed applicability of dpMIG-seq for allele dosage genotyping and are expected to catalyze the adoption of this cost-effective and rapid genotyping technology in polyploid studies.

A machine learning approach towards assessing consistency and reproducibility: an application to graft survival across three kidney transplantation eras.

In South Africa, between 1966 and 2014, there were three kidney transplant eras defined by evolving access to certain immunosuppressive therapies defined as Pre-CYA (before availability of cyclosporine), CYA (when cyclosporine became available), and New-Gen (availability of tacrolimus and mycophenolic acid). As such, factors influencing kidney graft failure may vary across these eras. Therefore, evaluating the consistency and reproducibility of models developed to study these variations using machine learning (ML) algorithms could enhance our understanding of post-transplant graft survival dynamics across these three eras. This study explored the effectiveness of nine ML algorithms in predicting 10-year graft survival across the three eras. We developed and internally validated these algorithms using data spanning the specified eras. The predictive performance of these algorithms was assessed using the area under the curve (AUC) of the receiver operating characteristics curve (ROC), supported by other evaluation metrics. We employed local interpretable model-agnostic explanations to provide detailed interpretations of individual model predictions and used permutation importance to assess global feature importance across each era. Overall, the proportion of graft failure decreased from 41.5% in the Pre-CYA era to 15.1% in the New-Gen era. Our best-performing model across the three eras demonstrated high predictive accuracy. Notably, the ensemble models, particularly the Extra Trees model, emerged as standout performers, consistently achieving high AUC scores of 0.95, 0.95, and 0.97 across the eras. This indicates that the models achieved high consistency and reproducibility in predicting graft survival outcomes. Among the features evaluated, recipient age and donor age were the only features consistently influencing graft failure throughout these eras, while features such as glomerular filtration rate and recipient ethnicity showed high importance in specific eras, resulting in relatively poor historical transportability of the best model. Our study emphasises the significance of analysing post-kidney transplant outcomes and identifying era-specific factors mitigating graft failure. The proposed framework can serve as a foundation for future research and assist physicians in identifying patients at risk of graft failure.

Heterogeneous Nucleation and Enhanced Charge Transfer via Amorphous Metal‐Organic Frameworks for Efficient and Stable Perovskite Solar Cells

AbstractThe two‐step sequential deposition method is considered a potential way for the large‐scale manufacture of perovskite solar cells (PSCs) with high power conversion efficiency and reproducibility. However, the dense lead iodide (PbI2) film interferes with its full contact with organic solutions, resulting in an inadequate reaction at the interface. Herein, 2 kinds of metal‐organic framework (MOF) are introduced, amorphous Ni‐MOF‐74 (amNi‐MOF‐74) and crystalline Zn‐MOF‐74 (crZn‐MOF‐74), into PbI2 for regulating crystallization. Compared to crZn‐MOF‐74, the incorporation of amNi‐MOF‐74 exhibited rapid nucleation, resulting in high‐quality perovskite films with large grain size, low trap density, and enhanced charge transfer between the perovskite and charge transfer layers. Meanwhile, the content of unstable phase PbI2 left in perovskite films due to insufficient reaction is also reduced. The amNi‐MOF‐74 modified PSCs exhibited a champion power conversion efficiency of 24.17% with good humidity and thermal stability. The unencapsulated device maintains 90% of its initial efficiency after 1000 h storage in dark ambient conditions with ≈30% relative humidity. This strategy provides an effective approach for promoting the crystallization process of perovskite and fabricating efficient and stable PSCs.

Feature selection by replicate reproducibility and non-redundancy.

A fundamental step in many analyses of high-dimensional data is dimension reduction. Two basic approaches are introduction of new synthetic coordinates and selection of extant features. Advantages of the latter include interpretability, simplicity, transferability, and modularity. A common criterion for unsupervized feature selection is variance or dynamic range. However, in practice, it can occur that high-variance features are noisy, that important features have low variance, or that variances are simply not comparable across features because they are measured in unrelated numeric scales or physical units. Moreover, users may want to include measures of signal-to-noise ratio and non-redundancy into feature selection. Here, we introduce the RNR algorithm, which selects features based on (i) the reproducibility of their signal across replicates and (ii) their non-redundancy, measured by linear dependence. It takes as input a typically large set of features measured on a collection of objects with two or more replicates per object. It returns an ordered list of features, i1,i2,…,ik, where feature i1 is the one with the highest reproducibility across replicates, i2 that with the highest reproducibility across replicates after projecting out the dimension spanned by i1, and so on. Applications to microscopy-based imaging of cells and proteomics highlight benefits of the approach. The RNR method is available via Bioconductor (Huber W, Carey VJ, Gentleman R et al. (Orchestrating high-throughput genomic analysis with bioconductor. Nat Methods 2015;12:115-21.) in the R package FeatSeekR. Its source code is also available at https://github.com/tcapraz/FeatSeekR under the GPL-3 open source license.

Flexible Temperature Sensor with High Reproducibility and Wireless Closed-Loop System for Decoupled Multimodal Health Monitoring and Personalized Thermoregulation.

Temperature and pulse waves are two fundamental indicators of body health. Specifically, thermoresistive flexible temperature sensors are one of the most applied sensors. However, they suffer from poor reproducibility of resistivity; and decoupling temperature from pressure/strain is still challenging. Besides, autonomous thermoregulation by wearable sensory systems is in high demand, but conventional commercial apparatuses are cumbersome and not suitable for long-term portable use. Here, a material-design strategy is developed to overcome the problem of poor reproducibility of resistivity by tuning the thermal expansion coefficient to nearly zero, precluding the detriment caused by shape expansion/shrinkage with temperature variation and achieving high reproducibility. The strategy also obtains more reliable sensitivity and higher stability, and the designed thermoresistive fiber has strain-insensitive sensing performance and fast response/recovery time. A smart textile woven by the thermoresistive fiber can decouple temperature and pulse without crosstalk; and a flexible wireless closed-loop system comprising the smart textile, a heating textile, a flexible diminutive control patch, and a smartphone is designed and constructed to monitor health status in real-time and autonomously regulate body temperature. This work offers a new route to circumvent temperature-sensitive effects for flexible sensors and new insights for personalized thermoregulation.

Simultaneous Electrochemical Determination of Hydroquinone, Catechol and Bisphenol A using Nickel Oxide@Reduced Graphene Oxide Nanocomposites in Water Samples

Phenolic compounds, prevalent in both human life and the natural environment, pose a significant threat to human health due to their toxic effects. Therefore, accurate determination of these compounds are crucial. Herein, we developed a new electrochemical sensor based on a NiO/C@reduced graphene oxide nanocomposite (NiO/C@rGO) to simultaneously assess three phenolic compounds: hydroquinone (HYQ), catechol (CAT), and bisphenol A (BPA). The NiO/C@rGO nanocomposite was synthesized via Ni(gallate)@GO pyrolysis and extensively characterized using various techniques. Subsequently, a glassy carbon electrode (GCE) modified with the NiO/C@rGO nanocomposite was utilized as the electrochemical sensor to simultaneously detection. The developed nanosensor (NiO/C@rGO/GCE) exhibited exceptional selectivity and a broad linear ranges for HYQ, CAT, and BPA, spanning from 0.01 to 100 μM, with impressively low detection limits. Furthermore, the NiO/C@rGO nanocomposite demonstrated remarkable stability and high reproducibility. Moreover, we successfully applied the NiO/C@rGO-based sensor to evaluate the three phenolic compounds in tap water, drinking water, and mineral water samples. The results underscore the potential of the developed electrochemical sensor as a reliable tool for the sensitive and fast detection of phenolic compounds in various water sources, addressing the critical need for safeguarding human health and the environment from their adverse effects.

DIB‐BOT: An Open‐Source Hardware Approach for Plate‐Integrated Droplet Interface Bilayer Deposition

AbstractDroplet interface bilayers (DIBs) offer a controlled lipid environment for studying membrane‐bound processes, with applications in artificial cells, biosensing, and biophysics. Current DIB fabrication faces challenges due to time‐consuming processes and specialized equipment, limiting scale‐up and hindering statistical significance in single‐molecule assays. This research introduces “DIB‐BOT,” an open‐source solution combining a nanoinjector and a 3D printer. DIB‐BOT enables rapid, reproducible DIB fabrication, overcoming manual limitations. Using off‐the‐shelf components, DIB‐BOT ensures high spatial reproducibility, minimal user input, and scalable experiments. The system's utility is demonstrated through pairwise droplet assembly and a fluorescence plate‐reader assay. Compared to manual fabrication, DIB‐BOT shows a 10‐fold reduction in droplet volume error, a threefold reduction in positional error, and 100% droplet yield. This method lowers entry barriers to DIB research, expanding its applications and enhancing data quality.

Synthesis and Characterization of a Novel Modified Biosensor Carbon/Chitosan L-Leucine and Albumin Electrode for Bilirubin and Uric Acid Blood Detection

Bilirubin (BR) is a yellow-to-orange bile pigment produced by hemoglobin breakdown. It circulates in the blood, is absorbed by the liver, and then conjugated to form bilirubin diglucuronide. Its increased level in serum (Hyperbilirubinemia) may considered as an indication of certain diseases such as neonatal jaundice, hepatitis, and severe liver failure with cirrhosis. Thus, the monitoring of BR in plasma is clinically important. Herein, a novel carbon/chitosan paste electrode modified by L-leucine and Albumin (C/Chi-PL-BSA) is synthesized and tested for electrochemical sensitive determination of BR and Uric Acid. Significate sensitivity and important selectivity in the linear range of 1.00–150.00 μM for BR, and 10.00–600.00 μM for UA were obtained. Moreover, micromolar detection limits of 0.40 μM for BR and 1.00 μM for UA were achieved at pH13. The proposed oxidation mechanisms of BR and UA in alkaline media have been supported by DFT calculations at the B3LYP/ 6–31 G(d) level of theory. The easy preparation and high reproducibility made this electrode very appropriate in pharmaceutical preparations for the electrochemical determination of BR. Furthermore, Analyses using human serum were performed, demonstrating a high percentage of recovery.

Application of a UV-vis spectrometer to investigate the effect of dissolution media on the diffusivity of small molecules and proteins

To date, the commonly used methods for diffusion coefficient measurements have some hurdles that prevent them from being widely applied in pharmaceutical laboratories. This study aimed to modify a method developed by di Cagno et al. based on the use of a UV-Vis spectrometer and apply the method to investigate the effect of dissolution media on the diffusivity of small molecules and proteins. A total of five small molecules and two proteins in different aqueous media and polymer solutions were investigated in this study. By attaching a 3D-printed cover with an open slit to a standard UV-Vis cuvette, the incident UV light could only pass through the open slit to measure the local drug concentration. During the diffusion experiment, drug molecules diffused from the cuvette bottom to the slit. According to the concentration measured as a function of time, diffusion coefficient was calculated based on Fick's law of diffusion using the analytical and numerical approaches. As a result, diffusion coefficients could be accurately measured with high reproducibility. The results also suggested that different media could affect the diffusion coefficients of small molecules by < 10% and proteins by < 15%. Since the UV-Vis spectrometer is a routine instrument, this method can potentially be employed by many pharmaceutical laboratories for diffusion coefficient measurements.

Quality control of traditional Chinese medicine Chelidonii herba based on 2D-Q-NMR

Chelidonii herba is a traditional Chinese medicinal herb with effects including antispasmodic, analgesic, antitussive, and bronchodilator properties. Alkaloids are the main bioactive ingredients in Chelidonii herba. In this study, a two-dimensional nuclear magnetic resonance (Heteronuclear Singular Quantum Correlation, HSQC-2D-NMR) technique was employed to quantitatively analyze the total alkaloid content and three major active alkaloid monomers in Chelidonii herba from eleven different sources. The quantification results of the three monomeric alkaloids were also verified using conventional quantitative control methods such as HPLC. Experimental findings indicate that the total alkaloid content is not directly correlated with the content of the three monomeric alkaloids. Furthermore, the content of any individual monomeric alkaloid does not accurately reflect the overall quality of Chelidonii herba. It was demonstrated that the 2D-Q-NMR NMR can be applied as an alternative method. While maintaining the same levels of accuracy and precision, the 2D-Q-NMR method is simpler to operate and provides more comprehensive results with higher reproducibility in some cases.

Development of Fe3O4/DEX/PDA@Au(Raman reporters)@Au-MPBA nanocomposites based multi-hotspot SERS probe for ultrasensitive, reliable, and quantitative detection of glucose in sweat

Glucose is a key biomarker of diabetes, and effective glucose monitoring methods are crucial to the prevention and management of diabetes. Therefore, in this paper, Fe3O4/DEX/PDA@Au (Raman reporters) @Au nanocomposites were synthetized that with DTNB (5,5′-dithiobis(2-nitrobenzoic)), MMTA (2-mercapto-4-methyl-5-thiazole acetic acid), MBA (4-mercaptobenzoic acid) and 4-Mpy(4-Mercaptopyridine) were used separately as Raman reporters. Fe3O4 and PDA (Polymerized dopamine) could supply more high surface area of active sites and high SERS (Surface-Enhanced Raman Scattering) substrate, which has high stability and reproducibility. Dextran coating is an effective way to prepare biocompatible materials TEM, XRD, TG and VSM were used to analyze the size, morphology and magnetic properties of the nanocomposites. Fe3O4/DEX/PDA@Au(Raman reporters)@Au that integrates a multi-hotspot structure and magnetic separation techniques were studied the enhancement effect of Raman spectra, and glucose solutions with different concentrations were tested. Furthermore, the optimal Fe3O4/DEX/PDA@Au(Raman reporters)@Au nanocomposites were supplied as SERS substrates for detection of glucose accurately and quickly in sweat. SERS signal intensity is linearly correlated with glucose concentration within the measurement range of 5 × 10-3 to 10 mM, and the minimum detectable concentration is 5 µM. The Fe3O4/DEX/PDA@Au(Raman reporters)@Au nanocomposites exhibit high reliability, specificity and repeatability of the strategy were then verified by practical detection of sweat.

Determination of ten bisphenols and five parabens in urine by solid supported liquid-liquid extraction and liquid chromatography-tandem mass spectrometry

Bisphenols (BPs) and parabens (PBs) are of great concern for environmental pollution and human health because of their endocrine-disrupting effects and potential health hazards. Urinary biomonitoring of BPs and PBs can provide basic data for human internal exposure evaluation, which is a prerequisite for accurately assessing their health risks. In this study, we developed a new pretreatment procedure based on solid supported liquid-liquid extraction (SLE) for the simultaneous separation of ten BPs and five PBs in human urine, followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. In the instrumental analysis, the HPLC conditions and MS/MS parameters were comprehensively optimized. Accurate qualitative and quantitative determination of ten BPs and five PBs was achieved by introducing a ternary gradient elution system of water, methanol, and acetonitrile for LC separation. During sample pretreatment, the extraction solvent and elution volume were optimized. Specifically, urine samples were held at room temperature and centrifuged at 3000 r/min for 10 min. The supernatant (2 mL) was then transferred to a glass tube, and the pH was adjusted to 5.0 using HCl (0.5 mL; 0.1 mol/L) and NaAc-HAc buffer (1.5 mL). Thereafter, β-glucuronidase-arylsulfatase (20 μL) and surrogate standard solutions (10 ng;13C12-BPS,13C12-BPAF,13C6-MeP, and 13C6-BuP) were added, and the mixture was incubated in a shaker bath in the dark at 37 ℃ for 16 h. After incubation, the hydrolyzed sample (4 mL) was loaded onto an SLE cartridge and equilibrated for a minimum of 5 min to ensure the solution was completely absorbed by the packing material. Subsequently, the target chemicals were eluted with a mixed ethyl acetate/n-hexane solution (3∶7, v/v; 15 mL). Separation of the targets was performed on a ZORBAX SB-C18 reversed-phase column (250 mm×4.6 mm, 5 μm) using an acetonitrile-methanol-water system as the mobile phase. The method was verified by spiking mixed urine samples at three levels (1, 5, and 50 μg/L), with the recoveries ranging from 84.3% to 119.8%. Except for bisphenols (BPS), whose matrix effect was calculated as -21.8%, the matrix effects of other analytes were lower than 20%, indicating low matrix interference. The linear ranges of the analytes varied from 0.1-500 μg/L to 1-500 μg/L, with correlation coefficients higher than 0.995. The method limits of quantification for target chemicals ranged from 0.03 to 0.30 μg/L, and the relative standard deviations of intra- and inter-day experiments were 1.4%-8.4% and 5.7%-14.6%, respectively, suggesting high stability and reproducibility. The method was successfully applied to the determination of ten BPs and five PBs in 10 urine samples from a general population. The concentrations of target chemicals in the human urine samples varied. Methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and bisphenol A (BPA) were detected in all samples, with median mass concentrations of 1.10, 0.60, 0.21, and 0.55 μg/L, respectively. The detection rates of the other chemicals were less than 50%, which may be related to the production and use of specific chemicals, their bioavailability, and biological metabolism in humans.

Eco-friendly one-step egg white gel preparation for sensitive detection of 13 trichothecenes in oats using UHPLC-MS/MS.

Oat products have gained widespread recognition as a health food due to their rich and balanced nutritional profile and convenience. However, the unique matrix composition of oats, which differs significantly from other cereals, presents specific challenges for mycotoxin analysis. This study presents an ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method enhanced with an innovative egg white gel pretreatment for the simultaneous analysis of 13 regulated and unregulated trichothecenes in oats. The method demonstrated excellent performance with high accuracy (> 87.5%), repeatability (< 5.7%), and reproducibility (< 8.1%). Analysis of 100 commercial oat products revealed a concerning detection rate (78%) for at least one of the 11 trichothecenes investigated. Notably, deoxynivalenol, exceeding the standard limit in 2% of samples, exhibited the highest detection rate (62%). Additionally, concerning co-occurrence patterns and positive correlations were observed, highlighting potential synergistic effects. The first-time detection of unregulated mycotoxins (T-2 triol, 4,15-diacetoxyscirpenol, 15-acetoxyscirpenol, and neosolaniol) underscores the need for comprehensive monitoring. This method, while developed for oats, shows potential for broader application to other cereals, though further investigation and confirmation are necessary. These findings suggest a potentially underestimated risk of trichothecenes in oats, necessitating continuous monitoring to ensure consumer safety.

Facile, eco-friendly and sensitive fluorimetric approach for detection of chlorpromazine: Application in biological fluids and tablet formulations as well as greenness evaluation of the analytical method.

Monitoring antipsychotic drugs in biological fluids, such as human serum and urine, is important for ensuring the safety and efficacy of psychiatric treatments. This process helps maintain therapeutic drug levels, minimize side effects, and optimize patient well-being. Chlorpromazine (CZ) is a widely prescribed antipsychotic drug used for conditions like schizophrenia, bipolar disorder, and acute psychosis. Almost all existing sensing techniques for CZ are either insensitive spectrophotometric methods or involve long and complex chromatographic procedures, limiting their routine use. In this work, we introduce a facile, green, and sensitive fluorimetric strategy with high reproducibility for detecting CZ in its pure form, tablet formulation, and spiked human plasma and urine without the need for derivatization reactions. The proposed method relies on the inhibition of the intramolecular photoinduced electron transfer (PET) effect by using 2.0 M acetic acid. This approach enables the linear detection of CZ from 3.0 to 600 ng/mL with remarkably low quantitation and detection limits of 1.51 and 0.49 ng/mL, respectively. Moreover, the developed method's greenness was evaluated.

Silicon quantum dots based fluorescent probes for detecting methyl parathion pesticide residues in potato, tap water and Yellow River

In this paper, a novel ratiometric fluorescent probe based on silicon quantum dots (SiQDs) has been developed for the sensitive detection of methyl parathion pesticide residues. The silicon quantum dots were prepared by a simple hydrothermal reaction process using 3-Aminopropyltriethoxysilane (APTES) as silicon resource and were characterized by the analysis of transmission electron microscopy, FTIR spectroscopy, and X-ray photoelectron spectroscopy. The silicon quantum dots displayed characteristic blue fluorescence emission at 440 nm. Tyrosinase can catalyze the oxidation of tyramine to form dopamine. Then, dopamine can interact with silicon quantum dots and effectively change the position of its fluorescence emission for redshiftting to 540 nm. In the presence of organic phosphorus pesticides (OPPs), the activity of tyrosinase was inhibited, resulting in the inability to generate dopamine and the fluorescence emission at 440 nm remaining unchanged. As a model of organic phosphorus pesticides, methyl parathion (MP) was determined using this method, and the fluorescence intensity response values showed a good linear relationship with methyl parathion concentration in the range of 50–90 nM, with a detection limit of 0.149 nM. Due to its good performance of relative low detection limit, good selectivity and high reproducibility, this sensing system has been successfully applied to the detection of methyl parathion in environmental water samples and potato samples, which showed good prospects for application in the detection of organic phosphorus pesticide residues in more real samples.

DC vs AC Electrokinetics-Driven Nanoplasmonic Raman Monitoring of Charged Analyte Molecules in Ionic Solutions.

Electrokinetic surface-enhanced Raman spectroscopy (EK-SERS) is an emerging high-order analytical technique that combines the plasmonic sensitivity of SERS with the electrode interfacial molecular control of electrokinetics. However, previous EK-SERS works primarily focused on non-Faradaic direct current (DC) operation, limiting the understanding of the underlying mechanisms. Additionally, developing reliable EK-SERS devices with electrically connected plasmonic hotspots remains challenging for achieving high sensitivity and reproducibility in EK-SERS measurements. In this study, we investigated the use of two-tier nanolaminate nano-optoelectrode arrays (NL-NOEAs) for DC and alternating current (AC) EK-SERS measurements of charged analyte molecules in ionic solutions. The NL-NOEAs consist of Au/Ag/Au multilayered plasmonic nanostructures on conductive nanocomposite nanopillar arrays (NC-NPAs). We demonstrate that the NL-NOEAs exhibit high SERS enhancement factors (EFs) of ∼106 and can be used to modulate the concentration and orientation of Rhodamine 6G (R6G) molecules at the electrode surface by applying DC and AC voltages. We also performed numerical simulations to investigate the ion and R6G dynamics near the electrode surface under DC and AC voltage modulation. Our results show that AC EK-SERS can provide additional insights into the dynamics of molecular transport and adsorption processes compared to DC EK-SERS. This study demonstrates the potential of NL-NOEAs for developing high-performance EK-SERS sensors for a wide range of applications.