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The article focuses on writing high impact paper for building a professional career. Writing and describing the work in a clear, concise, but interesting manner, moves a paper from being good to being exceptional. If the same experimental work is described by two different writers, very different levels of manuscripts can result. Great science when written poorly can be a good paper or alternatively, average science when written well can be a good paper. Sometimes when reviewing a manuscript, it seems that authors even skip the basic steps like using the "spell check" features in all word processing programs or confirming text referencing to the numbers in the list of references.

An interview is presented with recipients of the Analytical and Bioanalytical Chemistry (ABC) Best Paper Award 2013 including Sherrie Elzey, regional sales manager at the precision measuring tools manufacturer TSI Inc., and De-Hao Tsai, assistant professor at the National Tsing Hua University, Beijing, China. Topics discussed include their inspiration for doing research in nanoparticle analysis, merits of the award for their work and the influence of research on bioanalytical particles.

Leukocytes play a crucial role in clinical diagnosis. The noninvasive and immediate detection of this low blood component has both important application and academic significance. The "M + N" theory makes it obvious that suppressing the influence of N factors and reducing the influence of M factors are both necessary in order to accurately detect the low content of blood components like leukocytes. Therefore, based on the strategy of "fixing the influencing factors" in the "M + N" theory, this paper proposes the method of "partition modeling based on the content of large concentrations of non-target components." Firstly, a dynamic spectral acquisition system was built to achieve the noninvasive acquisition of spectra. Then this paper applies the method proposed above to the modeling process of the samples. In order to lessen the impact of the M factors, the approach first divides the samples into groups based on the concentrations of the major blood components (platelets and hemoglobin). This reduces the range of fluctuation of the non-target components in each interval. The modeling of the leukocyte content was then carried out independently for each sample contained in each compartment. Compared with the result of modeling the sample directly, the related coefficient of the calibration set (Rc) improved by 11.70%, and the root mean square error (RMSEC) decreased by 76.97%; the related coefficient of the prediction set (Rp) improved by 32.68%, and the root mean square error (RMSEP) decreased by 52.80%. When the model was applied to predict all samples, the related coefficient (R-all) increased by 16.67%, and the root mean square error (RMSE-all) dropped by 63.00%. It was shown that, as compared to direct modeling of leukocyte concentration, the method of "partition modeling based on the content of large concentrations of non-target components" considerably increased the accuracy of quantitative analysis of leukocytes. The method can be used to analyze other blood components as well, offering a fresh approach and technique to increase the precision of spectral analysis of the blood's small content components. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) pandemic is currently a serious global health threat. While conventional laboratory tests such as quantitative real-time polymerase chain reaction (qPCR), serology tests, and chest computerized tomography (CT) scan allow diagnosis of COVID-19, these tests are time-consuming and laborious, and are limited in resource-limited settings or developing countries. Point-of-care (POC) biosensors such as chip-based and paper-based biosensors are typically rapid, portable, cost-effective, and user-friendly, which can be used for COVID-19 in remote settings. The escalating demand for rapid diagnosis of COVID-19 presents a strong need for a timely and comprehensive review on the POC biosensors for COVID-19 that meet ASSURED criteria: Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, and Deliverable to end users. In the present review, we discuss the importance of rapid and early diagnosis of COVID-19 and pathogenesis of COVID-19 along with the key diagnostic biomarkers. We critically review the most recent advances in POC biosensors which show great promise for the detection of COVID-19 based on three main categories: chip-based biosensors, paper-based biosensors, and other biosensors. We subsequently discuss the key benefits of these biosensors and their use for the detection of antigen, antibody, and viral nucleic acids. The commercial POC biosensors for COVID-19 are critically compared. Finally, we discuss the key challenges and future perspectives of developing emerging POC biosensors for COVID-19. This review would be very useful for guiding strategies for developing and commercializing rapid POC tests to manage the spread of infections. Graphical abstract [ABSTRACT FROM AUTHOR]

This work presents a portable microfluidic paper-based analytical device (micro-PAD) card for the quantification of total ammonia nitrogen in human saliva. The amount of total ammonia nitrogen in saliva can be an indicator of the status of the oral microbiome with potential correlation to kidney health problems. The developed micro-PAD card comprises twenty units consisting of three stacked layers of circular discs: the sample layer, paper discs impregnated with sodium hydroxide solution, the PTFE membrane layer, and the detection layer, paper discs impregnated with bromothymol blue. The twenty units were aligned on transparent laminating pouches laminated to form the micro-PAD card (7.5 cm × 10.5 cm). Saliva samples can be directly dispensed onto the micro-PAD card and the detection was achieved by the BTB indicator color change, from yellow to blue, after conversion of ammonium into ammonia and diffusion of the ammonia gas through a hydrophobic layer. The determination of total ammonia nitrogen in saliva using the developed micro-PAD card intended to be very simple method and operated without the need of laboratory equipment. A quantification limit of 11.3 NH4+mg L-1 and linear application range from up to 150 NH4+mg L-1 were obtained making it suitable for the expected concentrations of total ammonia nitrogen in human saliva. It was successfully applied to saliva samples and its validation obtained by comparison against a potentiometric method. The card is stable for at least 1 month making it ideal as a portable device for point-of-care diagnosis. [ABSTRACT FROM AUTHOR]

The article announces that Wei Sun has the 2008 Best Paper Award from "Analytical and Biochemical Chemistry" for his research in differential interference contrast (DIC) microscopy.

The author discusses a study conducted by German chemist Eberhard Denk, which won the 2007 Best Paper Award from the "Analytical and Bioanalytical Chemistry" journal. The study examined an isotopic technique that can be used to develop strategies to prevent osteoporosis. It proposed a technique that calls for the labeling calcium in the bone matrix isotropically. The article also provides a profile of Denk.

The article focuses on several aspects of reviews for assessing the manuscripts. Good reviews are easy to deal with. Praise is readily accepted. Those that accept a paper without changes are pleasantly unexpected since such reviews are usually only a small fraction. In contrast, negative reviews can be both ego deflating and difficult. Rejection is hard to accept for anyone on anything, but that does not mean it is not warranted. Getting a manuscript published despite initial negative reviews is possible. Almost all manuscripts receive some negative reviews. Every author should understand that any scientist, even the most successful and renowned, has received a negative review of a manuscript.

Heparan sulfate (HS) proteoglycans regulate a number of biological functions in many systems. Most of the functions of HS are attributed to its unique structure, consisting of sulfated and non-sulfated domains, arising from the differential presence of iduronyl and glucuronyl residues along the polysaccharide chain. A single glucuronyl C5-epimerase enzyme acts on HS precursors, converts glucuronyl residues into iduronyl residues, and modulates subsequent biosynthetic steps in vivo. Previously, the ratios of non-sulfated epimers within the polysaccharide chain have been calculated by resolving radiolabeled GlcA-Man and IdoA-Man disaccharides using a tedious paper chromatography technique. This radioactive assay, based on measuring either the release or incorporation of H at C5 carbon of uronyl residues of H-labeled HS precursor substrate, has been in use over three decades to characterize the action of HS C5-epimerase. We have developed a non-radioactive assay to estimate the epimerase activity through resolving GlcA-Man and IdoA-Man disaccharides on high-performance liquid chromatography in conjunction with hydrogen/deuterium exchange upon epimerization protocol-liquid chromatography mass spectrometry (DEEP-LC-MS). Utilizing this new, non-radioactive-based assay, DEEP-LC-MS, we were able to determine the extent of both forward and reverse reactions on the same substrate catalyzed by C5-epimerase. The results from this study also provide insights into the action of C5-epimerase and provide an opportunity to delineate snapshots of biosynthetic events that occur during the HSPG assembly in the Golgi. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Volatile organic compounds emitted from a several decade series of bound periodicals (1859-1939) printed on ground wood paper, as well as historical books dating from the 1500s to early 1800s made from cotton/linen rag, were studied using an improved headspace SPME/GC-MS method. The headspace over the naturally aging books, stored upright in glass chambers, was monitored over a 24-h period, enabling the identification of a wide range of organic compounds emanating from the whole of the book. The detection of particular straight chain aldehydes, as well as characteristic alcohols, alkenes and ketones is correlated with oxidative degradation of the C fatty acid constituency of paper. The relative importance of hydrolytic and oxidative chemistry involved in paper aging in books published between 1560 and 1939 was examined by comparing the relative abundances of furfural (FUR) a known cellulose hydrolysis product, and straight chain aldehydes (SCA) produced from the oxidation of fatty acids in paper. The relative abundance of furfural is shown to increase across the 379-year publication time span. A comparison of relative SCA peak areas across the series of books examined reveals that SCA emission is more important in the cotton/linen rag books than in the ground wood books. [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00216-021-03299-3 [ABSTRACT FROM AUTHOR]

The author argues on publishing of 50 research papers and manuscripts in an entire career.

The Italian dialect poet Cesare Pascarella travelled all around the world, noting down in notebooks his keen and caustic observations, and drawing sketches that are a visual reportage of his journeys. The sketches were mounted as a random collage over acidic cardboards that were exposed to direct sunlight in his studio. Their poor state of conservation is related to the use of modern paper: chemical instability of raw materials caused acidification and strong oxidation of the support, with intense yellowing of the surfaces and brittleness of the paper. To ensure future preservation of the drawings, chemical stabilisation with simultaneous alcoholic treatment by deacidification (calcium propionate) and reduction (borane tert-butylamine complex) appeared necessary. To verify its applicability, it was indispensible to characterise the support and identify the nature of all the graphic media. The use of Raman, Infrared, X-ray fluorescence spectroscopies and scanning electron microscopy coupled with X-ray microanalysis allowed us to clear the problems related to the different penetration depth of each analytical technique and the different responses of pigments/dyes to each spectroscopy. The palette, how it varied along the journeys, the different supports used and preparations were completely identified showing a choice of colours compatible with the reduction treatment. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Non-invasive identification of organic colourants in paintings still remains a challenging issue, especially in the case of extremely thin layers of paint on printed paper such as Japanese ukiyo-e prints. Because prints are fragile artworks, various non-invasive analytical methods need to be employed. The present work focuses on results obtained by combining fibre optic reflectance spectroscopy in the near-infrared range (FORS NIR) with mid-infrared (MIR) spectroscopy. The first step consists of identifying spectroscopic marker bands typical of some organic pigments (indigo, gamboge, cochineal, turmeric, safflower, dragon’s blood). Some reference printouts involving paper substrate, binder and pigments (seldom used or as mixtures) were then investigated in order to establish a straightforward way to extract the marker bands of the pigments. Some data post-treatments were applied to the spectra, such as spectral subtraction, in order to abstract the signal from overlapping bands originating from both substrate and binder, and second derivative calculation to emphasise the pigment marker bands’ frequency positions. These data treatments turned out to be relevant to extract information on the organic pigments of interest, even within complex mixtures. [ABSTRACT FROM AUTHOR]

This article presents information on a conference Jornadas de Análisis Instrumental (JAI), held in November 2002, at Barcelona, Spain. The meeting of JAI describes a very interesting approach to the extraction, purification and characterization of synthetic crudes of peptide hormones of therapeutical interest. The rigorous and useful methodology proposed is characteristic of analytical proteomics and it is being imported to trace element speciation investigations. It could be said that nowadays the JAI in Spain is playing a role which is reminiscent of that played in the U.S. by the well known Pittsburgh Conference: it is a great occasion for manufacturers to show the latest instruments and methodologies of modern analytical science in the instrument exhibition to scientists and users attending the JAI scientific meeting.

By using a silver nanoparticle wiper as a surface-enhanced Raman scattering substrate, a highly sensitive, convenient, and rapid platform for detecting dye adulteration of medicinal herbs was obtained. Commercially available filter paper was functionalized with silver nanoparticles to transform it into the flexible wiper. This device was found to collect dye molecules with unprecedented ease. Experiments were performed to optimize various factors such as the type of wiper used, the wetting reagent, and the wetting/wiping mode and time. Excellent wiper performance was observed in the detection of the simulated adulteration of samples with dyes at various concentrations. The limits of detection for nine dyes, including 10 g/mL for malachite green, 10 g/mL for Rhodamine 6G, and 5 × 10 g/mL for methylene blue, were discerned. The results of this investigation show that this proposed method is potentially highly advantageous for field-based applications. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The growth of the field of lipidomic analysis is enormous with numerous papers published annually, as shown on the statistics from Web of Science for keywords "lipidomic(s)" and "mass spectrometry" (Fig. The detailed analysis of these papers shows the approximate relative portions for major analytical approaches in lipidomic analysis: 59% liquid chromatography, 29% shotgun (direct infusion), and 12% mass spectrometry imaging. Is almost exclusively based on mass spectrometry (MS) analysis [[7]], starting from low-resolution analyzers (typical QqQ), now shifting more towards tandem mass analyzers with ultrahigh resolving power, e.g., Orbitraps. [Extracted from the article]

Cystic fibrosis is one of the most common life-shortening, childhood-onset inherited diseases. Among the 1,000 known cystic fibrosis-related mutations, DF508 is the most common, with a frequency varying between 50% and 70% according to geographical areas and population typology. In this work, we report the use of methylene blue as an electrochemical reporting agent in the discrimination of synthetic PCR analogue of the DF508 cystic fibrosis mutation (Mut) from the wild type (Wt). At optimum experimental condition, a discrimination factor between mutant and wild type of approximately 1.5-fold was found. The proposed assay was quantitative and linear in the range of 10–100 nM, exhibiting a limit of detection of 2.64 nM. Electrochemical studies at variable ionic strength conditions allowed further elucidation of the mechanism of the methylene blue (MB)–DNA interaction. To the best of our knowledge, this is the first report of detection of hybridisation solely via guanine-specific MB–DNA interaction simultaneously in MB solution, independent of electrostatic interaction as demonstrated in the ionic strength study. The introduction of formamide in the hybridization buffer, to improve discrimination, was also investigated. Finally, mutant wild type discrimination was demonstrated, at 10 nM concentration, with the use of a multi-sensor setup. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The methylene blue method has been widely used for analysis of sulfide for more than 100 years. Direct measurement of methylene blue at nanomolar concentrations is impossible without a preconcentration step, however. In this study the response of LC–MS with electrospray ionization (ESI) to methylene blue was evaluated. HPLC with simple isocratic elution was followed by ESI-MS quantification, which was compared with traditional UV–visible detection. The limit of detection for sulfide was approximately 50 ng L−1, or 1.5 nmol L−1. Analysis time was substantially reduced by use of isocratic elution. Interfering compounds produced by side reactions can be eliminated by use of the mass filter. A polysulfide sample was also analyzed to determine which products are formed and whether or not polysulfides react stoichiometrically with methylene blue reagent. It seems that polysulfides do not react quantitatively with methylene blue and so cannot be quantified reliably by use of this method. [ABSTRACT FROM AUTHOR]

In view of the high toxicity and widespread availability, it is of great importance to develop accurate, sensitive, and convenient assays for fluoride ion (F−) detection. Herein, a ratiometric fluorescent system is established for point-of-care testing (POCT) of F− with a smartphone as analyzer. The sensing system of calcein-QDs-Eu3+ contains two fluorescent probes of calcein (green emission) and ZnCdSe/ZnS QDs (red emission). The sensing system only presents red emission in that the calcein emission is quenched due to the combination between calcein and Eu3+. When F− is introduced, the fluorescence of calcein is recovered due to the stronger interaction between F− and Eu3+, which changes the emission from red to green. The ratiometric strategy offers an obvious fluorescence color change of the system, which eliminates interference and improves the detection accuracy. Specifically, the sensing system has excellent selectivity in that Eu3+ is more inclined to bind with F− rather than other anions. The developed assay was further used to prepare a test paper and hydrogel for POCT. To further improve the detection sensitivity and realize quantitative analysis, a smartphone installed with a color scan app is integrated as signal reader and analyzer, which is used for POCT of F− in real samples, showing great application potential in environmental protection and food safety evaluation. [ABSTRACT FROM AUTHOR]

Vertical flow assays have been developed in recent years addressing limitations of the lateral flow assays, including limited multiplexing capability, quantitation, and hook effect. In the present study, the first passive paper-based vertical flow assay is developed for the detection of the nucleic acid target. Horseradish peroxidase was used as an enzymatic tracer with a high potential for signal amplification. In order to achieve the best signal-to-noise ratio, different parameters of paper-based assays were optimized. The sample is heat denatured and hybridized with a specific probe to form a dual-labeled hybridization complex. A small volume of diluted sample, 12 µl, can be analyzed within 6 min on the assay in a sandwich format. Assay specificity was evaluated by testing different unrelated samples, and also, 1.7 nM was obtained as the limit of detection (LOD) using the 0 + 3SD method, which is equivalent to 8.5 fmol of double-stranded DNA in the 12 µl sample volume. The linear range of 3–194 nM with a 0.978 correlation coefficient was obtained according to the calibration curve. The developed assay was evaluated with 45 hepatitis B virus clinical plasma samples, and the result showed 100% consistency of the assay with the real-time PCR benchmark. In the present study, we sought to develop a mere detection system for nucleic acid targets, and to investigate the possibility of using enzyme reporter in a passive vertical flow assay. [ABSTRACT FROM AUTHOR]

Point-of-care (POC) real-time polymerase chain reaction (PCR) has become one of the most important technologies for many fields such as pathogen detection and water-quality monitoring. POC real-time PCR usually adopts chips with small-volume chambers for portability, which is more likely to produce complex noise that seriously affects the accuracy. Such complex noises are difficult to be eliminated by the traditional fixed area algorithm that is most commonly used at present because they usually have random shape, location, and brightness. To address this problem, we proposed a novel image analysis method, Dynamic Deep Learning Noise Elimination Method (DIPLOID), in this paper. Our new method could recognize and output the mask of the interference by Mask R-CNN, and then subtract the interference and select the maximum valid contiguous area for brightness analysis by dynamic programming. Compared with the traditional method, DIPLOID increased the accuracy, sensitivity, and specificity from 57.9 to 94.6%, 49.1 to 93.9%, and 65.9 to 95.2%, respectively. DIPLOID has great anti-interference, robustness, and sensitivity, which can reduce the impact of complex noise as much as possible from the aspect of the algorithm. As shown in the experiments of this paper, our method significantly improved the accuracy to over 94% under the complex noise situation, which could make the POC real-time PCR have greater potential in the future. [ABSTRACT FROM AUTHOR]

A recently developed blood typing diagnostic based on a polyester thread substrate has shown great promise for use in medical emergencies and in impoverished regions. The device is easy to use and transport, while also being inexpensive, accurate, and rapid. This study used a fluorescent confocal microscope to delve deeper into how red blood cells were behaving within the polyester thread-based diagnostic at the cellular level, and how plasma separation could be made to visibly occur on the thread, making it possible to identify blood type in a single step. Red blood cells were stained and the plasma phase dyed with fluorescent compounds to enable them to be visualised under the confocal microscope at high magnification. The mechanisms uncovered were in surprising contrast with those found for a similar, paper-based method. Red blood cell aggregates did not flow over each other within the thread substrate as expected, but suffered from a restriction to their flow which resulted in the chromatographic separation of the RBCs from the liquid phase of the blood. It is hoped that these results will lead to the optimisation of the method to enable more accurate and sensitive detection, increasing the range of blood systems that can be detected. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The article announces that David Calligaris has won the 2015 ABC Best Paper Award.

In this work, green-emitting carbon quantum dots were successfully prepared through a facile one-step solid-state reaction method. The obtained green-emitting carbon dots (G-CDs) showed good fluorescence stability in NaCl aqueous solution and different pH values. Moreover, the G-CDs showed high sensitivity and selectivity for detecting hypochlorite by both fluorometry and colorimetry. Under the optimized condition, a highly sensitive detection of hypochlorite was established in the range of 0.2–100 μM and 10–150 μM for fluorescent and colorimetric methods, respectively. The corresponding limits of detection (LOD) were 0.0781 μM and 1.82 μM, respectively. Therefore, the G-CDs were successfully applied to determinate hypochlorite in actual water samples. In addition, a paper-based sensor loading with the G-CDs was also developed for rapid visual detection of hypochlorite. The results suggested that the G-CDs could be a promising candidate to detect hypochlorite. [ABSTRACT FROM AUTHOR]

Although some ratiometric fluorescent sensors have been reported to detect tetracyclines, most of ratiometric fluorescent sensors were established based on europium ion with a narrow linear range. In this work, a ratiometric fluorescent sensor for tetracyclines detection was established based on the dual-emission lanthanum-doped carbon dots (La-CDs) as probes combining with the characteristic pH-response of tetracyclines. The fluorescence intensity of tetracyclines will be enhanced in high pH, and the emission peak of tetracyclines overlapped with the peak of probes. The superposition effect of tetracyclines and probes at 515 nm greatly improved the sensitivity of the ratiometric fluorescent sensor and widened the detection range, and linear ranges for oxytetracycline (OTC) and tetracycline (TC) were respectively 0.00–805.20 μM and 0.00–1039.50 μM. Moreover, the preparation procedure of the La-CDs was simple and time saving and the coupling agent was not required. A comparison of La-CDs with undoped carbon dots (un-CDs) showed that the optical performance and sensing performance of La-CDs were improved. In addition, a portable paper sensor with La-CDs as probes was preliminarily explored in this work, and the sensor has been applied to detect OTC and TC in pork and fish with satisfactory results. [ABSTRACT FROM AUTHOR]

Microfluidic devices can provide a versatile, cost-effective platform for disease diagnostics and risk assessment by quantifying biomarkers. In particular, simultaneous testing of several biomarkers can be powerful. Here, we critically review work from the previous 4 years up to February 2021 on developing microfluidic devices for multiplexed detection of biomarkers from samples. We focus on two principal approaches: electrical and optical detection methods that can distinguish and quantify biomarkers. Both electrical and spectroscopic multiplexed detection strategies are being employed to reach limits of detection below clinical sample levels. Some of the most promising strategies for point-of-care assays involve inexpensive materials such as paper-based microfluidic devices, or portable and accessible detectors such as smartphones. This review does not comprehensively cover all multiplexed microfluidic biomarker studies, but rather provides a critical evaluation of key work and suggests promising prospects for future advancement in this field. [ABSTRACT FROM AUTHOR]

The article announces that Jean-Philippe Frimat has received the 2010 Best Paper Award for outstanding work published by journal.

In this paper, we proposed an efficient method for mercury(II) and glutathione detection using a fluorescent nanoprobe as a sensor. Carbon dots were synthesized from polyethyleneimine and ammonium citrate via a one-step hydrothermal method. The fluorescence of carbon dots was quenched since electron transfer occurred due to the interaction between mercury(II) and functional groups on the surface of carbon dots. Adding glutathione to the carbon dots-mercury(II) system, the fluorescence was recovered due to the stronger binding ability of glutathione to mercury(II). Based on the above-mentioned principle, this "off-on" fluorescent sensor can easily achieve the detection of mercury(II) and glutathione, which provided limits of detection of 22.45 nM and 61.89 nM, respectively. In this paper, the proposed method has been applied to detect mercury(II) and glutathione in real lake water and serum, respectively, and a logic gate for sensing glutathione was presented. The developed "off-on" fluorescent sensor with high sensitivity and selectivity has shown great potential for mercury(II) and glutathione detection in environmental and biosensing fields. [ABSTRACT FROM AUTHOR]

The article presents an interview with Clint M. Alfaro, Doctor of Philosophy candidate in analytical chemistry at Purdue University. Topics discussed include he talks about motivation to do research on touch spray-mass spectrometry and its intraoperative applications; his valuable achievement in research was ambient ionization mass spectrometry results; and his future plans on becoming chemistry research faculty member and translational scientist.

Non-invasive blood composition analysis based on dynamic spectrum (DS) theory has gained significant attention due to its non-invasive, simple, and fast performance. However, most of the multi-wavelength photoplethysmography (PPG) detection devices used to obtain DS are composed of halogen light sources and spectrometers and cannot detect effective PPG signals in the visible light short band (400–620 nm), which limits the detection accuracy of blood components with significant absorption spectral differences in that band. Therefore, this paper designs a multi-wavelength spectral acquisition system that can measure high signal-to-noise ratio (SNR > 65 dB) PGG signals at wavelengths of 405, 430, 450, 505, 520, and 570 nm and combines this system with a halogen lamp spectrometer acquisition system for non-invasive blood component detection. Furthermore, this paper collects the DS of 272 subjects with the combined system and establishes a predictive model for DS with the content of red blood cell (RBC) and hemoglobin (HGB) components. The results show that, compared with the halogen lamp spectrometer acquisition system, the correlation coefficient (Rp) of RBC and HGB prediction model established by the combined system has increased by 0.0619 and 0.0489, respectively, and the root mean square error (RMSE) has decreased by 0.08 1e12/L and 0.85 g/L, which confirm the feasibility of the designed multi-wavelength spectrum acquisition system to enhance the accuracy of blood component detection. [ABSTRACT FROM AUTHOR]

A novel and simple method utilizing a chromogenic reaction on filter paper is introduced for the rapid screening of banned aromatic amines released from azo dyes. The proposed method involves the sample preparation protocols outlined by the current standard method and the chromogenic reaction of extracted aromatic amines on filter paper. Based on the principle of the reaction between primary amines and aldehydes, p-dimethylaminobenzaldehyde (DMAB) was used as the chromogenic reagent for the rapid screening of 24 carcinogenic aromatic amines and aniline without any chromatographic instruments under optimized experimental conditions. The detection limit for all the aromatic amines in this study was less than 15 mg/kg. A total of 727 dyed textile samples were analyzed using both the present standard method and the proposed method simultaneously. Using the proposed method, a total of 471 samples did not require further instrumental analysis, which can dramatically save instrumental detection time (61.2%), can decrease instrumental detection costs, and can avoid the use of large amounts of toxic reagents. The proposed method has been applied to detect banned aromatic amines in some inspection institutions and dye factories and has large social and economic benefits.Chromogenic reaction methods [ABSTRACT FROM AUTHOR]

Ambient mass spectrometry provides great convenience for fast screening, and has showed promising potential in analytical chemistry. However, its relatively low sensitivity seriously restricts its practical utility in trace compound analysis. In this review, we summarize the sampling and analyte enrichment strategies coupled with nine modes of representative ambient mass spectrometry (desorption electrospray ionization, paper vhspray ionization, wooden-tip spray ionization, probe electrospray ionization, coated blade spray ionization, direct analysis in real time, desorption corona beam ionization, dielectric barrier discharge ionization, and atmospheric-pressure solids analysis probe) that have dramatically increased the detection sensitivity. We believe that these advances will promote routine use of ambient mass spectrometry. [ABSTRACT FROM AUTHOR]

Phosphatidylethanol (PEth) is a group of phospholipids formed in cell membranes following alcohol consumption by action of the enzyme phospholipase D (PLD). PEth measurement in whole blood samples is established as a specific alcohol biomarker with clinical and forensic applications. However, in blood specimens containing ethanol, formation of PEth may continue after sampling leading to falsely elevated concentrations. This study evaluated the use of dried blood spot (DBS) and microsampling specimens to avoid post-sampling formation of PEth. Filter paper cards and three commercial devices for volumetric microsampling of finger-pricked blood were assessed, using PEth-negative and PEth-positive whole blood fortified with 2 g/L ethanol. PEth (16:0/18:1) was measured by LC–MS/MS. Post-sampling formation of PEth occurred in wet blood and in the volumetric devices, but not filter paper cards, when stored at room temperature for 48 h. Addition of an inhibitor of PLD, sodium metavanadate (NaVO3), eliminated post-sampling formation during storage and drying. In conclusion, the present study confirmed previous observations that PEth can be formed in blood samples after collection, if the specimen contains ethanol. The results further demonstrated that post-sampling formation of PEth from ethanol also occurred with commercial devices for volumetric dried blood microsampling. In order for a PEth result not to be questioned, it is recommended to use a PLD inhibitor, whether venous blood is collected in a vacutainer tube or finger-pricked blood is obtained using devices for dried blood microsampling. [ABSTRACT FROM AUTHOR]

Hydrazine is a highly toxic and flammable liquid that can damage human liver, kidney, and central nervous system. Therefore, it is valuable to seek a quick and sensitive method for hydrazine detection in environmental and biological science. Herein, a new fluorescent probe derived from 3-hydroxyphthalimide was synthesized. This probe can rapidly and selectively detect hydrazine with a low detection limit of 4.3 × 10−7 M. The recognition principle is based on hydrazine-induced acetyl deprotection and excited-state intramolecular proton transfer (ESIPT) process. Moreover, test paper and fluorescence image experiments showed that this probe had potential to monitor hydrazine in the environment and living cells. [ABSTRACT FROM AUTHOR]

Concerns about environmental and food contamination caused by chlortetracycline (CTC) residues have prompted people to explore efficient and convenient CTC monitoring platforms. However, the reported fluorescent probes generally fail to selectively detect CTC due to the structural similarity of tetracycline antibiotics. Herein, an intrinsic dual-emission carbon dots (D-CDs) ratiometric fluorescence sensor was prepared for highly sensitive and selective determination of CTC over other tetracyclines by one-step synthesis. The sensor exhibited a significant fluorescence enhancement at 425 nm after introducing CTC. The fluorescence "turn on" of the sensing system is due to aggregation-induced emission (AIE) phenomenon formed by hydrogen bonds and π conjugation promoting the specific recognition of CTC by D-CDs. The linear detection varied from 0.98 to 143.67 ng mL−1 with a low limit of detection (LOD) of 1.29 ng mL−1 (R2 = 0.998), which was lower than most reported in the literature. The D-CDs sensor was applied to detect CTC in spiked milk, blocked normal human serum, and fish samples with recoveries of 95.5–104.2% and relative standard deviations (RSDs) of 2.6%. Particularly, D-CDs based test papers with a smartphone were prepared for portable and visual detection of CTC by analyzing the various color changes of RGB of fluorescence color, with an LOD of 7.18 ng mL−1 (R2 = 0.9909). The fluorescence sensor designed in this work could be used as a rapid tool with high performance and selectivity for monitoring control in foods. [ABSTRACT FROM AUTHOR]

Malaria is an infectious disease that can cause severe sickness and death if not diagnosed and treated in a timely manner. The current gold standard technique for malaria diagnosis is microscopy, which requires a dedicated laboratory setting and trained personnel and can have a long time to result. These requirements can be alleviated using paper-based diagnostic devices that enable rapid and inexpensive diagnosis at the point of care, which can allow patients to receive treatment before their symptoms progress when used for early detection of diseases. The lateral-flow immunoassay (LFA) is one such device, but currently available LFAs are susceptible to false negative results caused by low parasite density. To improve sensitivity and detection, we utilized the aqueous two-phase system (ATPS) to concentrate and purify the sample, and nanozyme signal enhancement to increase the intensity of the visible signal on the test strip. We were able to achieve a limit of detection (LOD) of 0.01 ng/mL for the malaria biomarker Plasmodium lactate dehydrogenase (pLDH) in human serum using a multi-step assay combining the LFA format with the ATPS and nanozyme signal enhancement. [ABSTRACT FROM AUTHOR]

The detection of phytohormones in real time has attracted increasing attention because of their critical roles in regulating the development and signaling of plants, especially in defense against biotic stresses. Herein, stainless steel sheet electrodes modified with carbon cement were coupled with paper-based analysis devices for direct and simultaneous detection of salicylic acid (SA) and indole-3-acetic acid (IAA) in plants. We demonstrated that the excellent conductivity of stainless steel sheet electrodes enabled us to simultaneously differentiate IAA and SA at a level of 10 nM. With our approach, the content of IAA and SA in Arabidopsis thaliana leaves infected or not infected with Pst DC3000 could be rapidly quantified at the same time. Our experimental results on differentiation of IAA and SA at different time points showed that there were antagonistic interactions between the IAA and SA after infection of Arabidopsis leaves with Pst DC3000. By offering a cost-effective approach for rapid and sensitive detection of IAA and SA, this study suggests that electrochemical detection can be used in the study and development of precision agriculture technology. [ABSTRACT FROM AUTHOR]

Dried blood spots (DBS) are being considered as an alternative sampling method of blood collection that can be used in combination with lipidomic and other omic analysis. DBS are successfully used in the clinical context to collect samples for newborn screening for the measurement of specific fatty acid derivatives, such as acylcarnitines, and lipids from whole blood for diagnostic purposes. However, DBS are scarcely used for lipidomic analysis and investigations. Lipidomic studies using DBS are starting to emerge as a powerful method for sampling and storage in clinical lipidomic analysis, but the major research work is being done in the pre- and analytical steps and procedures, and few in clinical applications. This review presents a description of the impact factors and variables that can affect DBS lipidomic analysis, such as the type of DBS card, haematocrit, homogeneity of the blood drop, matrix/chromatographic effects, and the chemical and physical properties of the analyte. Additionally, a brief overview of lipidomic studies using DBS to unveil their application in clinical scenarios is also presented, considering the studies of method development and validation and, to a less extent, for clinical diagnosis using clinical lipidomics. DBS combined with lipidomic approaches proved to be as effective as whole blood samples, achieving high levels of sensitivity and specificity during MS and MS/MS analysis, which could be a useful tool for biomarker identification. Lipidomic profiling using MS/MS platforms enables significant insights into physiological changes, which could be useful in precision medicine. [ABSTRACT FROM AUTHOR]

The outbreak rate of human coronaviruses (CoVs) especially highly pathogenic CoVs is increasing alarmingly. Early detection of these viruses allows treatment interventions to be provided more quickly to people at higher risk, as well as helping to identify asymptomatic carriers and isolate them as quickly as possible, thus preventing the disease transmission chain. The current diagnostic methods such as RT-PCR are not ideal due to high cost, low accuracy, low speed, and probability of false results. Therefore, a reliable and accurate method for the detection of CoVs in biofluids can become a front-line tool in order to deal with the spread of these deadly viruses. Currently, the nanomaterial-based sensing devices for detection of human coronaviruses from laboratory diagnosis to point-of-care (PoC) diagnosis are progressing rapidly. Gold nanoparticles (AuNPs) have revolutionized the field of biosensors because of the outstanding optical and electrochemical properties. In this review paper, a detailed overview of AuNP-based biosensing strategies with the varied transducers (electrochemical, optical, etc.) and also different biomarkers (protein antigens and nucleic acids) was presented for the detection of human coronaviruses including SARS-CoV-2, SARS-CoV-1, and MERS-CoV and lowly pathogenic CoVs. The present review highlights the newest trends in the SARS-CoV-2 nanobiosensors from the beginning of the COVID-19 epidemic until 2022. We hope that the presented examples in this review paper convince readers that AuNPs are a suitable platform for the designing of biosensors. [ABSTRACT FROM AUTHOR]

Interlayer spray is proposed as a convenient ionization source for direct analysis by mass spectrometry. Two slices of non-absorbent substrate hold the liquid sample to form a sandwich structure. By applying a high voltage to the sample, spray is generated at the tip of the substrate. The sampling procedure can be operated easily in an open condition and the spray is processed in a semi-enclosed condition, which leads to a relatively stable process. An ultralow amount (<2 μL) of the liquid sample can be analyzed without dilution, which ensures that the natural concentration and properties of the target are maintained. Less influence from the substrate is achieved compared with the spray methods based on porous absorbent materials, which results in a sensitivity enhancement of large molecule samples. It is demonstrated that the interlayer spray is applicable for the analysis of various compounds, including therapeutic drugs, peptides, and proteins. Good linearity can be obtained at a concentration as low as 50 ng/mL in the quantitative analysis for imatinib. We also show the ability to identify the chemical residuals on surfaces with high sensitivity by the 'wipe-spray' method, which is useful for the fast screening of illicit substances. Interlayer spray working with mass spectrometry provides a promising method for direct analysis in an ambient environment. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

d-Phenylalanine (d-Phe) is a small chiral organic molecule that is both an important pharmaceutical intermediate and used as a calibrator for quantifying amino acids in liquid chromatography-circular dichroism. We have developed a process for a national certified reference material (CRM) for d-Phe following ISO 17034:2016. The identity of d-Phe was confirmed using mass spectrometry (MS) and nuclear magnetic resonance (NMR), infrared, and ultraviolet (UV) spectroscopy. The absolute optical conformation was also determined using circular dichroism (CD) spectroscopy and optical rotation measurements. Impurities were identified via liquid chromatography (LC) with a UV–Vis detector and a charged aerosol detector (CAD) and LC–MS. Both mass balance and quantitative NMR were employed for value assessment, and the associated uncertainty was evaluated. The certified purity was determined to be 0.995 ± 0.003 g/g, a validation that was confirmed by CD using l-Phe CRM as a calibrator. Twenty milligrams of raw material was packed in sealed brown glass tubes for storage, and no inhomogeneity was observed. Stability tests revealed that the d-Phe CRM remained stable at −20 °C for at least 26 months, at 4 °C for at least 14 days, and at 25 °C and 60 °C for at least 7 days. The d-Phe CRM can be used to ensure the accuracy and reliability of d-Phe quantitation in the pharmaceutical field and also as a calibrator to ensure traceability to the International System of Units (SI) for l-Phe quantitation and protein purity analysis using LC-CD methods. The approach outlined in this paper also has potential for use in the development of other chiral CRMs. [ABSTRACT FROM AUTHOR]

This paper reports a flexible glucose biosensor which is modified by a reduced-swelling and conductive zwitterionic hydrogel enzyme membrane that contains two forms of chemical cross-links. One chemical cross-linking is induced by thermal initiators and forms the basal network of the hydrogel. Another cross-linking is achieved by the coordination interactions between the multivalent metal ion Al3+ and anionic group -COO− of zwitterionic poly-carboxy betaine (pCBMA), which significantly increase the cross-linking density of the zwitterionic hydrogel, improving the reduced-swelling property and reducing the pore size. The better reduced-swelling property and reduced diameters of pores within the zwitterionic hydrogel make less glucose oxidase (GOx) leakage, thus significantly improving the enzyme membrane's service life. By introducing the Al3+ and Cl−, the conductivity of the zwitterionic hydrogel is enhanced approximately 10.4-fold. According to the enhanced conductivity, the reduced-swelling property, and the high GOx loading capacity of the zwitterionic hydrogel, the sensitivity of the biosensor with GOx/pCBMA-Al3+ is significantly improved by 5 times and has a long service life. Finally, the proposed GOx/pCBMA-Al3+ biosensor was applied in non-invasive blood glucose detection on the human body, verifying the capability in practice. [ABSTRACT FROM AUTHOR]

Mechanotransduction is the essential process that cells convert mechanical force into biochemical responses, and electrochemical sensor stands out from existing techniques by providing quantitative and real-time information about the biochemical signals during cellular mechanotransduction. However, the intracellular biochemical response evoked by mechanical force has been poorly monitored. In this paper, we report a method to apply local stretch on single cell and simultaneously monitor the ensuing intracellular biochemical signals. Specifically, a ferromagnetic micropipette was fabricated to locally stretch a single cell labeled with Fe3O4 nanoparticles under the external magnetic field, and the SiC@Pt nanowire electrode (SiC@Pt NWE) was inserted into the cell to monitor the intracellular hydrogen peroxide (H2O2) production induced by the local stretch. As a proof of concept, this work quantitatively investigated the elevated amount of H2O2 levels in single endothelial cell under different stretching amplitudes. This work puts forward a new research modality to manipulate and monitor the mechanotransduction at the single-cell level. [ABSTRACT FROM AUTHOR]

This paper describes the use of PolyJet 3D printing to fabricate microchip electrophoresis devices with integrated microwire electrodes for amperometric detection. The fabrication process involves 3D printing of two separate pieces, a channel layer and an electrode layer. The channel layer is created by 3D printing on a pre-fabricated mold with a T-intersection. For the electrode layer, a stencil design is printed directly on the printing tray and covered with a piece of transparent glass. Microwire electrodes are adhered over the glass piece (guided by underlaying stencil) and a CAD design of the electrode layer is then printed on top of the microwire electrode. After delamination from the glass after printing, the microwire is embedded in the printed piece, with the stencil design ensuring that alignment and positioning of the electrode is reproducible for each print. After a thermal bonding step between the channel layer and electrode layer, a complete electrophoresis device with integrated microelectrodes for amperometric detection results. It is shown that this approach enables different microwire electrodes (gold or platinum) and sizes (100 or 50 µm) to be integrated in an end-channel configuration with no gap between the electrode and the separation channel. These devices were used to separate a mixture of catecholamines and the effect of separation voltage on the potential voltage applied on the working electrode was also investigated. In addition, the effect of electrode size on the number of theoretical plates and limit of detection was studied. Finally, a device that contains different channel heights and a detection electrode was 3D-printed to integrate continuous flow sampling with microchip electrophoresis and amperometric detection. [ABSTRACT FROM AUTHOR]

Cytochrome P450 3A4 (CYP3A4) is a crucial enzyme in the metabolism of xenobiotics, particularly in drug metabolism interactions (DDIs), making it a significant factor in clinical drug use. However, current assay techniques are both laborious and costly, making it difficult to construct a high-throughput monitoring method that can be used in conjunction with the clinic. This poses certain safety hazards for drug combination. Therefore, it is crucial to develop a synchronized monitoring method for the inhibition and induction of CYP3A4. In this study, we utilized 3D culture technology to develop a HepaRG cells spheroid model. The CYP450 and transporter expression, the albumin secretion, and urea synthesis capacity characteristics were analyzed. The NEN probe was utilized as a tracer molecule for CYP3A4. The fluorescence intensity of metabolites was characterized by laser confocal technique to determine the inhibition and expression of CYP3A4 in the HepaRG cell spheroid model by the antibiotics for sepsis. The results indicate that the HepaRG sphere model successfully possessed the physiological phenotype of the liver, which could be used for drug interaction monitoring. Through positive drug testing, NEN probe was able to achieve bidirectional characterization of CYP3A4 induction and inhibition. The monitoring method described in this paper was successfully applied to drug interaction monitoring of commonly used antibiotics in sepsis patients, which is a convenient and rapid monitoring method. The proposed method offers a new strategy for monitoring CYP3A4-mediated drug-drug interactions with a high-throughput assay, which will help to improve the safety of clinical drug combination. [ABSTRACT FROM AUTHOR]

This paper introduces an enhanced technique for analyzing iron isotopes in complex marine and biological samples. A dedicated iron purification method for biological marine matrices, utilizing three ion exchange columns, is validated. The MC-ICPMS in pseudo-high-resolution mode determines precise iron isotopic ratios, with sensitivity improved through the DSN-100 desolvating nebulizer system and Apex-IR. Only 2 µg of iron on DSN versus 1 µg on Apex is needed for six replicates (30–60 times improvement) while 10 to 20 µg is required for a single measurement on a wet system considering the resolution power (Rp) is maintained at 11,000–13,000. The Ni-doping method with a Fe/Ni ratio of 1 yields more accurate isotopic ratios than standard-sample bracketing alone. Measurement reproducibility of triplicate samples from marine biological experiments on MC-ICPMS is ± 0.03‰ (2SD) for δ56Fe and ± 0.07‰ for δ57Fe (2SD). This study introduces a novel iron purification process specifically designed for marine and biological samples, enhancing sensitivity and enabling more reliable measurements with smaller sample sizes and reduced uncertainties. It proposes iron isotopic compositions for biological reference materials, offering a valuable reference dataset in diverse scientific disciplines. [ABSTRACT FROM AUTHOR]

Reproductive management significantly impacts dairy farm productivity, necessitating accurate timely pregnancy detection in cattle. This paper presents a novel handheld and portable fluorescence imaging system designed for quantitative assessment of pregnancy-specific biomarkers, addressing the limitations of current detection methods. The objective was to develop a cost-effective, at-farm solution for detecting pregnancy-specific protein B (PSPB) in bovine plasma samples. The system integrates an imaging module and a custom software application, enabling image capture, data processing, and PSPB concentration determination. Calibration utilizing known PSPB concentrations achieved a 0.6 ng/mL limit of detection. Validation encompassed a comparison with a standard ELISA method using 100 bovine plasma samples; minimal bias and good agreement were observed within the linear range of the calibration curve for both methods. The system offers portability, user-friendliness, and potential for multiplex detection, promising real-time, at-farm reproductive management. This study demonstrates the successful development and validation of a portable fluorescence imaging system, offering an efficient and accurate approach to detecting pregnancy-specific biomarkers in cattle. Its implications extend to improving dairy farm productivity by enabling timely and reliable reproductive management practices. [ABSTRACT FROM AUTHOR]

Metrology is the science of measurement and its applications, whereas biometrology is the science of biological measurement and its applications. Biometrology aims to achieve accuracy and consistency of biological measurements by focusing on the development of metrological traceability, biological reference measurement procedures, and reference materials. Irreproducibility of biological and multi-omics research results from different laboratories, platforms, and analysis methods is hampering the translation of research into clinical uses and can often be attributed to the lack of biologists' attention to the general principles of metrology. In this paper, the progresses of biometrology including metrology on nucleic acid, protein, and cell measurements and its impacts on the improvement of reliability and comparability in biological research are reviewed. Challenges in obtaining more reliable biological and multi-omics measurements due to the lack of primary reference measurement procedures and new standards for biological reference materials faced by biometrology are discussed. In the future, in addition to establishing reliable reference measurement procedures, developing reference materials from single or multiple parameters to multi-omics scale should be emphasized. Thinking in way of biometrology is warranted for facilitating the translation of high-throughput omics research into clinical practices. [ABSTRACT FROM AUTHOR]