Talanta Open最新文献

Accurate and reliable identification and analysis of the elemental composition of human blood serum is of utmost importance. The present investigation included the analysis of human blood serums for elemental composition using a metal mesh-supported CO₂ laser-induced breakdown spectroscopy under a helium gas environment at atmospheric pressure. In this study, a pulsed transversely excited atmospheric CO₂ laser with a wavelength of 10.64 µm and a pulse duration of 200 ns was applied to irradiate the human blood serum film placed on a copper metal to induce a luminous plasma. A significant increment of elemental signal intensity occurs by introducing a metal mesh covering the serum film. Qualitative and quantitative analyses have been conducted on the human blood serum's major, minor, and trace elements. The concentrations of elements in the human blood are estimated to be 9160 parts per million (ppm) for carbon (C), 174 ppm for calcium (Ca), 600 ppm for potassium (K), 1410 ppm for magnesium (Mg), 343 ppm for phosphorus (P), 2180 ppm for sodium (Na), and 48 ppm for iron (Fe). The results of the CO₂ LIBS method demonstrate a high level of concurrence with the results obtained by the conventional XRF method.

Many neonates’ manifest hyperbilirubinemia and jaundice during the first week following birth because of bilirubin accumulation in the blood. Newborns with severe hyperbilirubinemia develop neurotoxicity. Therefore, sensitive, accurate, cost-effective, and timely determination of bilirubin levels is highly desired. Herein, we present three simple systems of bilirubin assessment based on spectrophotometric, and digital imaging tools. Image-capturing devices pose a formidable challenge to sophisticated spectrophotometers and field-monitoring devices because of their simplicity and sensitivity. The first and second systems of bilirubin assessment, in solution, relied on spectrophotometric and conventional color responses of digital images collected with conventional or android smartphone camera, with LODs of 0.060–0.082 and LOQs of 0.200–0.273 ppm bilirubin. The third system utilized a microfluidic paper-based analytical device (μ-PAD) that is patterned with a wax printer on Whatman grade-1 chromatographic papers, with linear calibration graphs of up to 2.70,s and LODs of 0.035–0.040 and LOQs of 0.117–0.133 μg bilirubin/μ-PAD.

Alkylphenols are widely applied in the field of industry and agriculture, but their endocrine disrupting properties harm to human health. Moreover, alkylphenols often exhibit the low content in complex samples. Thus, we proposed magnetic covalent organic framework composites (Fe₃O₄@TatTpa) for efficient magnetic solid phase extraction (MSPE) of alkylphenols via hydrogen bonding, π-π and hydrophobic interactions. In combination with HPLC detection, good linearity (0.006–10 µg mL⁻¹) with R² (≥0.997) and low limit of detections (1.8–6 × 10⁻³ µg mL⁻¹) were realized for alkylphenols. The proposed method was successfully employed to determine alkylphenols in soft drink, black oolong tea, and watermelon samples with satisfactory recoveries (86.1–118.5 %) and relative standard deviations (6.3–14.8 %).

The dynamic changes of amniotic fluid during pregnancy are crucial for the development, protection, defense and nutrition of the fetus. Amniotic fluid contains a variety of trace biomarkers, such as microRNA, free DNA, reactive oxygen species, interleukin and metabolomics, etc., which are of great significance for fetal health, diagnosis and drug control of various diseases. This article reviews the latest advances in the detection of microbial markers in amniotic fluid, and introduces the methods of amniotic fluid collection and attention. In addition, the biological approach to amniotic fluid testing is discussed. Finally, the challenges of amniotic fluid sample testing are discussed, with a view to promoting the clinical application of amniotic fluid in the field of assisted reproduction.

We developed a novel cell separation method based on the mechanical properties using a sponge-like monolithic polymer (SPM) in a spin-column format capable of high throughput and mass processing for cell diagnosis and separation. The continuous large flow pores of the monolithic skeleton around 200 μm were expected to act as a sieving matrix for large flexible molecules such as cells larger than 10 μm in diameter, based not only on the size but also on the mechanical deformability of the cells. The passage rates of rigid polystyrene beads ranging in size from 1 to 10 μm were investigated and demonstrated that the spin column acted as a separation matrix rather than a size-based cut-off filter in the 60 and 200 μm pores of the SPM. Two cell types, adherent cells (HeLa cells) and suspension cells (THP-1 cells), showed different passage behavior in the spin column, and 70 % and 30 % of the cells, respectively, were trapped in the column and never eluted. To investigate how the mechanical deformability of the cells affects the passage behavior, glutaraldehyde treatment, which denatured the proteins and changed the elastic moduli, was performed and compared. As a result, the fixed cells drastically reduced the passage rate and became trapped inside the SPM column. These initial studies explored a new application field of SPM for high throughput cell separation based on the mechanical properties of the cells despite the same size, and contribute to a new cell assay method prior to cell transplantation.

Collective cell migration is an essential biological process. Migration behaviors of multiple cellular units depend on the mechanical and chemical properties of their scaffolds and the geometry of the cells. However, the mechanisms by which these properties synergistically regulate the collective cell characteristics remain unknown. A robust method is required to analyze collective cell migration. Therefore, in this study, we developed a new method for collective cell migration analysis using defined chemical, mechanical, and geometrical properties. Our method is based on a poly(acrylic acid) hydrogel, whose surface is functionalized with photocleavable poly(ethylene glycol) and a cell-adhesive peptide. By controlling the UV irradiation of the photoactivatable hydrogel, we created geometrically controlled cellular clusters and induced collective migration. Furthermore, chemical and mechanical cues exposed to cell clusters were manipulated depending on the surface density of the cell-adhesive peptide and crosslinking density of the hydrogel. As a proof of concept, we also demonstrated that the collective migration of epithelial cells was synergistically regulated by the chemical and mechanical properties of the scaffold. Our results suggest the new photoactivatable substrate as a promising tool for advanced molecular and mechanobiological analyses of collective cell migration.

In the present work, an optical sensing scheme was designed to detect the Al(III) ions based on a fluorescent probe. The synthesized probe N-(3-chloro)-salicylaldimine CSI receptor was developed using turn-on fluorescence enhancement. During the treatment process of Al(III) ions, the emission of the CSI probe was increased at 545 nm due to the formation of a 1:1 complex between the chemosensor and the Al(III) ions at room temperature. The gradual addition of Al(III) ions to the studied solution gradually enhanced the CSI emission. The other metal ions, including alkali, alkaline metal ions, and some transition metal ions, had no noticeable impact on the fluorescent intensity. The limit of detection (LOD) and (LOQ) were determined as 0.427 nM and 1.28 nM, respectively. The detection limit for this sensor is very low, demonstrating its remarkable selectivity and ultra-sensitivity. These impressive characteristics allow the detection of Al(III) ions at concentrations as low as 1.28 × 10⁻³ to 1 μM while highly selective even in the presence of other metal ions. EDTA solution at a concentration of 1 µM was used to make the sensor reversible. We also provide the fact that the CSI probe can be a promising optical chemical for detecting Al(III) ions in real samples.

After the passage of the Agriculture Improvement Act of 2018 (Farm Bill) that defined hemp as Cannabis sativa L. if it contained ≤0.3 % Δ9-THC on a dry weight basis, forensic laboratories were faced with the challenge of distinguishing marijuana from hemp in seized drug samples. This study reports the results of an interlaboratory validation of a previously developed qualitative decision-point assay for the differentiation of illegal marijuana from legal hemp, utilizing gas chromatography-mass spectrometry (GC–MS) with a 1 % Δ9-THC threshold. The method was validated in terms of selectivity, linearity, carryover, precision, accuracy, extract stability, dilution integrity, and measurement uncertainty. Other elements such as decarboxylation rate and potential for CBD interference were also evaluated. Specificity and positive predictive value were both 100 % using known cannabis reference materials. A total of 8 false negative results were observed among the 280 analyses, resulting in an overall assay sensitivity of 94 % and a negative predictive value of 95 %. The small number of false negative results near the 1 % threshold were attributed to decarboxylation inefficiency in some laboratories. While qualitative in nature, the measurement uncertainty of the assay at the 0.3 % Δ9-THC cutoff (legal threshold) using a 95.45 % confidence interval (k = 2) ranged from 12.2 % to 21.8 % among laboratories (equivalent to 0.3 % ± 0.04 % to 0.07 % Δ9-THC by weight). A one-year retrospective study across three agencies and fifteen laboratories was undertaken. Among the three agencies participating in the original study, 93–96 % of all suspected cannabis seizures yielded results above the administrative threshold of 1 % Δ9-THC (n = 3,288). The interlaboratory method development highlighted differences in performance between sites, ultimately improving the overall robustness of the method. Observations highlight the need for site-specific validation and vigilance. While multi-agency collaborations and interlaboratory validations are valuable, they do not replace the necessity for full, independent, and rigorous validation.

Background

Chemometric analysis is also a powerful tool that can be used in the preliminary stages of analytical methods optimization, but is also efficient in data processing. These new approaches may be the key to the analysis of proteins, carbohydrate, sphignolipids, polyphenols in different food components. Although there are challenges in identifying and annotating those compounds due to the limited availability of analytical standards and structural diversity.

Scope and approach

Chromatograms are a useful tool for learning more about the chemical make-up of the food being tested. This information can occasionally be implicit or presented in a subtle way. Therefore, to extract it, chemometric tools and data mining techniques are needed. A chromatogram's fingerprint allows for the possibility of performing both identity and quality testing on food. This viewpoint aims to offer a current assessment of chromatographic fingerprinting technique in the area of food authentication. Additionally, this methodology's limitations, absence from official analytical methods, and future directions are discussed. Novel techniques have been employed in the past few decades, ranging from high-pressure thin liquid chromatography (HPTLC) to mass spectrometry (MS) and other spectroscopic methods. In the last decade research developments, and the application of analytical methods in qualitative and quantitative studies of food components and their adulterants is reviewed in the present work. High-pressure Thin liquid chromatography (HPTLC) is hyphenated with high resolution mass spectrometry is particularly addressed due to its applicability in the targeted/untargeted metabolomic analysis of all food components.

Key findings and conclusions

In the current study, the HPTLC-MS technique was used to examine food components and food adulteration. The HPTLC-MS hyphenated techniques were found to be an extremely helpful method for the detection of food adulterants as well as the various food components, such as protein, carbohydrates, lipids, essential oils, and flavonoids, which were found to be effective as medicinally.

The existence of extremely toxic mercury contaminants in the environment, even at very low concentrations, poses severe human health issues. Mercury exposure may lead to various diseases, such as prenatal brain damage, cognitive severe, motion disorders, and Minamata diseases. Hence, developing an effective and selective method to detect Hg²⁺ in the environment and biological samples is of great interest. Amongst various Hg²⁺ detection techniques, fluorescent chemosensors offer more convenient procedures, affordable cost, high selectivity, and the capability to perform cell imaging for Hg²⁺ detection. Herein, a novel "turn-on" fluorescent chemosensor, Thiourea-DHP derivative (TUD), highly selective to Hg²⁺, was successfully developed. TUD was synthesized by cyclotrimerization of β-amino acrylate, followed by the thioacylation of the resulting dihydropyridine (DHP) with dimethylamino thiocarbonyl chloride. The Hg²⁺ detection by TUD displayed an astonishing naked-eye blue fluorescence signal under blacklight, exhibiting an LOD of 69 nM or 14 ppb at pH 7.4 in the HEPES buffer. Hg²⁺-induced hydrolytic desulfurization of the low fluorescent TUD to produce the strongly fluorescent urea-DHP (UD) is proposed as a mechanism for this fluorescence enhancement. The formation of UD was confirmed by ¹H NMR, ¹³C NMR, and HRMS. This detecting system of TUD provided excellent percentage recovery (>97 %) for the analysis of Hg²⁺ contaminants in real-environmental water samples. Besides, the TUD probe showed nontoxic properties in living cells towards RAW264.7 murine macrophage cell line even at high concentrations (100 µM). Our proposed TUD probe demonstrated superior sensitivity in pure aqueous media compared to current mercury-desulfurization fluorescent chemosensors. This sensing system proved effective for analysing Hg²⁺ contaminants in real-environmental water samples. Additionally, the nontoxic TUD probe successfully revealed the remarkable biocompatibility for Hg²⁺ detection in living cells.