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Worldwide attention is focused on microplastics environmental pollution, primarily for its potential negative effects on biota and human health. It is of great importance to identify standardized analytical methods to have an objective feedback about this concern. The recent regulation regarding the intentionally added microplastics content and the attention for the unintentional microplastics release are the basis of this work, whose topic is the development of an analytical method for microbeads (spheres) and microparticles (fragments) determination in certain cosmetic samples, in particular creamy samples. The method is based on Accelerated Solvent Extraction technique to remove all the sample matrix ingredients. The final suspension was then filtered on silicon membrane, for the following quali-quantitative micro-FTIR analysis, and on glass fibre membranes, for the gravimetric analysis. The method was developed for a theoretical microplastics concentration of 0.025 % (w/w) and allows a good recovery percentage. Working both by gravimetric evaluation and by micro-FTIR analysis gives more confident results and guaranties a proper identification and characterization of the filtered materials.

Considering the close association between cardiac troponin I (cTnI) level and various cardiovascular diseases, it becomes essential to explore sensitive and accurate detection methods for monitoring their levels in the early stages of disease. In this work, a magnetic dual-aptamer electrochemical sensor for cTnI detection was constructed in the first utilizing MOF-on-MOF-derived electrocatalyst as a signal amplifier in collaboration with high-efficient separation of magnetic beads (MBs). Employing zeolitic imidazolate framework-67 (ZIF-67) with high surface area as host MOF, MOF-on-MOF heterostructure (ZIF-67@PBA) was facilely prepared by in-situ growth of conductive prussian blue analogue (PBA) as guest MOF onto the surface of ZIF-67 with a simple ion-exchange method. After low-temperature calcination, N doped derived electrocatalyst (N-ZIF-67@PBA) was obtained with intact skeletons and pore structures of MOFs. This not only integrated bimetallic active centers with various valence states and diversiform nanostructures of dual MOF, but endowed N-ZIF-67@PBA 8.3-fold increase of electrocatalytic activity for catalytic amplification. Further using aptamer-modified MBs as capture carriers for recognizing and separating cTnI from complex samples with high specificity, the magnetic dual-aptamer sensor successfully achieved the sensitive detection of cTnI with a low detection limit of 0.31 fg/mL. This work provided a new viewpoint on the use of MOF-on-MOF-derived electrocatalyst for ultrasensitive electrochemical sensing analysis.

Exosomes, emerging as ideal non-invasive biomarkers for disease diagnosis and monitoring, have seldom been explored based on metabolite levels. In this study, we designed and synthesized a pH-responsive phase-transition bifunctional affinity nanopolymer (pH-BiAN) that could efficiently and homogeneously separate exosomes from urine. Specifically, poly-4-vinylpyridine (P4VP) was chosen as the pH-responsive polymer and simultaneously modified with two exosome-affinity components CD63 aptamer and distearoyl phosphoethanolamine (DSPE) through a one-step amide reaction at room temperature. By utilizing two distinct but synergistic affinity mechanisms-the immune affinity between CD63 aptamer and exosomal CD63 proteins, and hydrophobic interactions between the DSPE and the exosomal lipids-pH-BiAN can enable efficient and specific exosome separation. Moreover, during the urine exosome capture procedure, the pH-BiAN outperforms conventional solid exosome separation materials by remaining soluble in the urine sample, significantly enhancing mass transfer and contact efficiency. After exosome capture, pH-BiAN can quickly aggregate and convert to solid upon pH adjustment, allowing for easy centrifugation separation. Afterwards, multiple machine learning models were established by combining liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) untargeted metabolomics for isolated exosomes, and the clinical accuracy of the training and test sets was more than 0.919, which could well distinguish early osteoarthritis patients from healthy people.

Liver cancer seriously threatens the health of human beings. Studies have found that esterase is overexpressed in liver cancer cells. Therefore, esterase can be one of the biomarkers of liver cancer. Previous literature studies have shown that the structures of fluorescent probe detection groups significantly impact the probes themselves and enzyme detection. In this paper, three "off-on" esterase-activated fluorescent probes (RHO-1, RHO-2 and RHO-3) with different length of the carbon chains of the detection groups were designed and synthesized. Density functional theory (DFT) calculation and Michaelis-Menten equations were applied to study the optical properties and affinity with esterase of the probes. Compared with RHO-1 and RHO-2, RHO-3 showed superior optical properties and affinity with esterase. Subsequently, RHO-3 was further used to detect esterase activity in vitro and in vivo. RHO-3 was the first esterase-activated fluorescent probe applied to image-guided diagnosis and surgical resection of liver cancer. It was expected to be a promising molecular imaging diagnostic tool in clinical applications.

This study presents an analytical approach coupling novel ambient ionization sources with trapped ion mobility spectrometry (TIMS) and tandem mass spectrometry (MS/MS) for the rapid characterization of fentanyl analogs. Two ambient ionization sources were illustrated for minimal sample preparation and rapid analysis: electrospray ionization (nESI) and direct analysis in real time (DART). Fentanyl analogs can be separated using nESI-TIMS-MS/MS based on differences in their mobility and/or fragmentation pattern; reference mobility spectra are reported for 234 single standards. In contrast, DART-TIMS-MS/MS allowed for the characterization of 201 compounds due to differences in the protonation pattern and efficiency when compared to nESI. The TIMS high resolving power (R > 80) allowed baseline separation for most isomers and mobility trends were established for methylated and fluorinated isomers, with the more compact ortho-substituted analogs showing distinct separation from para- and meta-substituted species. This multi-dimensional strategy offers a comprehensive characterization of fentanyl analogs and other synthetic opioids with minimal sample preparation. This analysis shows significant potential for high-throughput screening (<5 min) and high sensitivity detection (

This study presents a gas chromatographic detector using alternating current (AC) discharged in air to generate μ-arc at atmosphereic pressure. This air-based μ-arc emission detector (μ-AED) was assembled by two stainless-steel syringe needles inside a quartz tube. The length of μ-arc (i.e., distance of discharge) measures 550 μm. The organic compounds with various functional groups were chromatographically separated and fed into the μ-AED. The intensity changes in the emission spectrum were recorded as these compounds passing through the μ-arc. When organic compounds pass through the μ-arc, the changes in emission intensity could go either increase or decrease depending on the input power and underlying mechanisms. It was found that when operating the μ-arc at relatively low power, organic samples present as negative peaks, and better S/N ratio were obtained. The detection limits (3σ/s) range from 209 pg for n-butyl acetate to 552 pg for 1-chloropentane. A selectivity study reveals that μ-AED is more sensitive to oxygen-containing and aromatic compounds. The μ-AED developed in this study demonstrates the simplest design with reasonable miniaturization. The direct discharge in air makes this μ-AED suitable for future application with μ-GC which uses scrubbed air as carrier gas and eliminates bulky gas cylinders.

Effective detection technologies in food safety with the merits of portable and on-site detection potential are always in pressing demand. Herein, we developed a nanopore-assisted Enzyme-linked immunosorbent assay (NELISA) platform, which innovatively introduced hairpin DNA (HP DNA) probes as reaction substrates. This innovation of substrates effectively avoided the inherent limitations of colorimetric signals (i.e., low sensitivity and inaccurate results) and greatly improved the sensitivity and accuracy of NELISA platform. The alkaline phosphatase (ALP)-modified detection antibody (ALP-Ab2) can specifically bind to ricin and hydrolyze the phosphate groups modified on the HP DNA probes. Nanopore recordings demonstrated that two states of probes produced highly distinguishable nanopore events, enabling the qualitative and quantitative detection of ricin. This NELISA platform fully combined the specificity of ELISA with the ultra-sensitivity, and unique single-molecule fingerprint recognition of nanopore, showing a great on-site detection potential. This method achieved the ultrasensitive and reliable detection of ricin down to 2.46 fg/mL, which enhanced the detection sensitivity by at least 10⁶-fold compared to traditional ELISA. Furthermore, the proposed method was capable of accurately detecting ricin in real food samples with satisfactory recoveries.

Epidermal Growth Factor Receptor (EGFR) is an important target for the early evaluation, treatment, and postoperative follow-up in non-small cell lung cancer (NSCLC). Current detection technologies suffer from extended detection time and high rate of false positive amplification. Therefore, the development of rapid, highly sensitive and specific detection methods is of great significance for improving the diagnosis and treatment of lung cancer. In this study, we proposed a fast and sensitive detection method termed Thermus thermophilus Argonaute (Ttago)-Coupled-Multiplex-digital-recombinase polymerase amplification (RPA)-Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a (TCMDC) detection method, integrating EGFR mutation template enrichment. Based on the cleavage principle of TtAgo, the wild type (WT) template was enriched under the action of double-guide DNA. Two CRISPR RNAs, not restricted by protospacer adjacent motif (PAM) sites, were introduced to target EGFR genes. By combining RPA with CRISPR-Cas12a, we established a single-pot, ultra-sensitive (1 copy, 0.1 %), and visually detectable method for EGFR detection. We further verified the feasibility of this approach using clinical serum samples from lung cancer patients, achieving rapid (within 1 h) and visual detection of EGFR, thereby presenting a promising clinical tool for the detection of lung cancer.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. The authors have plagiarized part of a paper that had already appeared in Nat. Commun.12, (2021) 658, https://doi.org/10.1038/s41467-021-20948-4. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Formaldehyde (HCHO) is a harmful volatile organic pollutant, which is commonly found in interior decoration and furniture products. Therefore, it is necessary to develop a gas sensor that can quickly and accurately detect formaldehyde for human health and environmental protection. In order to achieve this goal, in this work, SnS₂/SnO₂ heterostructure was synthesized by in-situ sulfurization process on the basis of SnO₂ nanospheres, and its formaldehyde sensing performance was studied. After testing, it was found that the gas sensor based on SnS₂/SnO₂ heterojunction has more excellent gas sensing performance than pure SnO₂ gas sensor at the same operating temperature (100 °C). Specifically, SnS₂/SnO₂-2 (Sn:S = 3:2) has the advantages of high sensitivity (4.01 at 0.1 ppm), excellent selectivity, low theoretical detection limit (13.26 ppb), good humidity resistance and long-term stability. The excellent sensing performance of SnS₂/SnO₂ sensors for formaldehyde detection is mainly attributed to the n-n heterojunction formed by SnS₂ and SnO₂, which generates a built-in electric field to accelerate the electron transport in the material, the higher oxygen vacancy sites adsorb a large number of reactive gas molecules to promote the oxidation of formaldehyde molecules, and the unique porous structure to promote the transmission and diffusion of gases and increase the surface area to provide more adsorption sites and reactive centers for gas molecules. Therefore, the construction of SnS₂/SnO₂ heterostructures will be an effective way to develop next-generation formaldehyde gas sensors with higher sensing performance.