Analyte Concentration Research Articles

An innovative triple interface reinforced photocatalytic system based on BiOCl/BaTiO3@Co-BDC-MOF composite for the simultaneous detoxification of Cr(VI) and sulfamethoxazole

The development of effective photocatalysts for the reduction of Cr(VI) and the degradation of antibiotics remains a challenge. The present work reports the development of a novel heterojunction composite material, BiOCl/BaTiO3@Co-BDC-MOF (BOC/BTO@Co-MOF), based on solvothermal techniques. To characterize the surface and bulk features of the material, techniques such as FE-SEM, HR-TEM, BET/BJH, XPS, FT-IR, p-XRD, and UV–Vis-DRS were used. Based on the results, the BiOCl/BaTiO3 nanocomposites are uniformly dispersed on the rod-shaped Co-BDC MOF, resulting in a layered texture on the surface. A further advantage of the composite structure is the strong interfacial enhancement facilitating the separation of photoexcited electron-hole pairs. Also, compared to its pristine counterparts, the heterostructure material exhibited excellent surface area and pore properties. The photocatalytic efficiency towards reduction and degradation of Cr(VI)/SMX pollutants were evaluated by optimizing various analytical parameters, such as pH, catalytic loading concentrations, analyte concentration, and scavenger role. The specially designed BOC/BTO@Co-MOF composite achieved a 96.5% Cr(VI) reduction and 98.2% SMX degradation under 60.0–90.0 min of visible light illumination at pH 3.0. This material is highly reusable and has a six-time recycling potential. The findings of this study contribute to a better understanding of the efficient decontamination of inorganic and organic pollutants in water purification systems.

Lifting the Concentration Limit of Mass Photometry by PEG Nanopatterning.

Mass photometry (MP) is a rapidly growing optical technique for label-free mass measurement of single biomolecules in solution. The underlying measurement principle provides numerous advantages over ensemble-based methods but has been limited to low analyte concentrations due to the need to uniquely and accurately quantify the binding of individual molecules to the measurement surface, which results in diffraction-limited spots. Here, we combine nanoparticle lithography with surface PEGylation to substantially lower surface binding, resulting in a 2 orders of magnitude improvement in the upper concentration limit associated with mass photometry. We demonstrate the facile tunability of degree of passivation, enabling measurements at increased analyte concentrations. These advances provide access to protein-protein interactions in the high nanomolar to low micromolar range, substantially expanding the application space of mass photometry.

Innovative disposable pipette extraction for concurrent analysis of fourteen psychoactive substances in drug users’ sweat

Widespread consumption of drugs of abuse worldwide has caused concern: it adversely affects public health, individual safety, and social structures. Experts are particularly alarmed because new psychoactive substances have been increasingly detected in biological samples. In recent years, several studies have focused on developing methods to identify psychoactive substances in alternative biological matrices, such as sweat. This approach holds promise for monitoring substance use, especially in individuals undergoing rehabilitation. Among the commonly employed analytical procedures, extraction using disposable DPX tips stands out as a novel, miniaturized, and promising technique. This study aimed to validate and to apply a method to analyze various substances, including amphetamine, methamphetamine, MDMA, MDA, MDEA, cocaine, cocaethylene, anhydroecgonine methyl ester, dibutylone, N-ethylpentylone, 25E-NBOMe, 25CNBOMe, 2CC, 2C-E, fentanyl, and carfentanil, in sweat samples simultaneously. In this method, sweat is collected by using laboratory-developed patches, and extraction is conducted with DPX-SCX tips. Gas chromatography coupled to mass spectrometry is employed to separate, to identify, and to quantify the analytes. Validation results indicated that the quantification limit ranged from 2 to 30 ng of analyte/patch, and that the method was linear for analyte concentrations ranging from 2 to 1100 ng/patch. The validated method was applied to analyze 30 sweat samples collected from volunteers drug users and processed by using both the selected ion mode (SIM) and full scan. The method was able to detect and to quantify substances such as cocaine, cocaethylene, anhydroecgonine methyl ester, MDMA, MDA, nicotine, cotinine, caffeine, procaine, lidocaine, and ethylamphetamine simultaneously. The recovery rates ranged from 72.4 % to 97.1 %. The analytes were stable in the biological matrix. In conclusion, the validated method proved effective and allowed the target analytes to be quantified in sweat samples, highlighting that sweat is a viable matrix for analyzing drugs of abuse.

Serum vitamin D metabolite and acute-phase protein concentrations are frequently abnormal in a cohort of hospitalized dogs and cats.

To determine whether serum 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) concentrations are associated with survival and negatively correlate with acute-phase protein (APP) concentrations in ill dogs and cats admitted to nursing care units. Client-owned dogs (n = 79) and cats (16) admitted to 2 academic veterinary hospital nursing care units. A prospective cohort study was conducted between August 12, 2019, and October 26, 2021. A diagnostic laboratory measured 25(OH)D, 1,25(OH)2D, and haptoglobin (HPT) in dogs and cats; C-reactive protein (CRP) in dogs; and serum amyloid A (SAA) in cats. Serum was collected within 12 hours of admission. Illness severity (acute patient physiologic and laboratory evaluation [APPLEfast]) scores and survival data were recorded. Serum 25(OH)D concentrations were in the deficient range for 22 of 79 dogs and 2 of 16 cats. There were no associations between serum analyte concentrations (25[OH]D, 1,25[OH]2D, and APP) or APPLEfast score and survival in dogs or cats. In dogs, HPT was negatively correlated with 25(OH)D (P = .002; r = -0.34) and 1,25(OH)2D (P = .012; r = -0.28), while CRP was positively correlated with HPT (P = .001; r = 0.32) and APPLEfast score (P = .014; r = 0.16). In cats, 1,25(OH)2D was negatively correlated with APPLEfast scores (P = .055; r = -0.49) and SAA was positively correlated with HPT (P = .002; r = 0.73). Serum 25(OH)D or 1,25(OH)2D was not associated with survival in our hospitalized patient population. Relationships between APP and serum vitamin D metabolites with APPLEfast scores in cats warrant further investigation as illness severity biomarkers.

Comparative evaluation of wavelength-scanning Otto and Kretschmann configurations of SPR biosensors for low analyte concentration measurement

Abstract The growing demand for compound characterization has stimulated research, particularly in surface plasmon resonance technology. This technique monitors changes in the light-reflecting properties of a sample medium in close contact and in interaction with a plasmonic surface (typically a metal such as gold) due to shifts in the fundamental plasmon resonance of the surface. The Otto and Kretschmann configurations are commonly used in this method. When an analyte is expensive, scarce, or hazardous, it is advantageous to reduce the sample required for testing, making optimization of sample use interesting. This challenge requires trade-offs between sensitivity and LoD. This work compares two sensors in the indicated configurations designed for minimal analyte requirement (in this case, Ag nanoparticle suspensions) using the wavelength scanning technique. The results show that the Kretschmann configuration is the most efficient for characterizing nanoparticle suspensions due to its construction characteristics, ease of use, and the characteristics of the obtained response. The final arrangement is a quasi-point sensor that only requires 6μL of analyte and has a sensitivity of 4.17x10−4 RIU/λ (RIU is the refractive index unit). This study contributes to the exploration of advantages and limitations in the design and operation of SPR sensors. The work also underlies the need for future research to enhance the selectivity and versatility of these devices.

LOW TEMPERATURE ANALYTICAL CLOUD POINT EXTRACTION. 2: PRECONCENTRATION AND SPECTROPHOTOMETRIC DETERMINATION OF GE(IV)

Cloud point extraction is a powerful tool for the analytical preconcentration of trace amounts of analytes. The standard cloud point extraction procedure requires prolonged heating of the solution, which is not always appropriate in the case of thermally unstable analytes or analytical forms and significantly limits the capabilities of the method. One of the ways to modify cloud point extraction is to find approaches to intensifying the process of analytical concentration. The main disadvantage of cloud point extraction is the need for thermal, ultrasonic, infrared or any other initiation of the formation of the surfactant rich phase. It has been shown that salts of aromatic carboxylic acids can cause instantaneous formation of a surfactant-rich phase. In this work, the conditions of micellar extraction concentration of Ge(IV) in the form of a complex with 6,7-dihydroxy-2-phenyl-4-methylbenzopyrylium bromide into the micellar phase of the nonionic surfactant triton X-100 were studied and optimized. It is shown that the introduction of ammonium benzoate into the system at a pH of 1.0 and a triton X-100 concentration of 0.5 vol.% leads to the initiation of the formation of a micellar phase at room temperature. The method of spectrophotometric determination of Ge(IV) with 6,7-dihydroxy-2-phenyl-4-methylbenzopyrylium bromide after its micellar- extraction concentration has been developed. The calibration graph is linear in the concentration range of 4.36–472 μg/L, and the limits of detection and determination are 1.31 and 4.36 μg/L, respectively. The proposed method was tested in the analysis of model solutions and biologically active additives, and the relative standard deviation does not exceed 5.1%.

Molybdenum Disulfide-Assisted Spontaneous Formation of Multistacked Gold Nanoparticles for Deep Learning-Integrated Surface-Enhanced Raman Scattering.

Several fabrication methods have been developed for label-free detection in various fields. However, fabricating high-density and highly ordered nanoscale architectures by using soluble processes remains a challenge. Herein, we report a biosensing platform that integrates deep learning with surface-enhanced Raman scattering (SERS), featuring large-area, close-packed three-dimensional (3D) architectures of molybdenum disulfide (MoS2)-assisted gold nanoparticles (AuNPs) for the on-site screening of coronavirus disease (COVID-19) using human tears. Some AuNPs are spontaneously synthesized without a reducing agent because the electrons induced on the semiconductor surface reduce gold ions when the Fermi level of MoS2 and the gold electrolyte reach equilibrium. With the addition of polyvinylpyrrolidone, a two-dimensional large-area MoS2 layer assisted in the formation of close-packed 3D multistacked AuNP structures, resembling electroless plating. This platform, with a convolutional neural network-based deep learning model, achieved outstanding SERS performance at subterascale levels despite the microlevel irradiation power and millisecond-level acquisition time and accurately assessed susceptibility to COVID-19. These results suggest that our platform has the potential for rapid, low-damage, and high-throughput label-free detection of exceedingly low analyte concentrations.

Revolutionizing biomarker analysis one tip at a time—Coupling antibody to Volumetric Absorptive Microsamplers for sensitive LC-MS analysis

The constant pursuit of efficient and cost-effective methods for analyzing human samples drives ongoing innovation in biomedical research. Introduced in 2014, Volumetric Absorptive Microsampling (VAMS) technology ensures fixed blood volume absorption and enhanced sample uniformity. Our study aims to enhance VAMS functionality by integrating sample preparation onto the device primarily used for sample collection. This involves the adsorption of antibodies onto VAMS tips, enabling instant sample clean-up at the time of sample collection. Using human chorionic gonadotropin (hCG) as a model analyte, we evaluated the qualitative and quantitative performance of Affinity-VAMS. First, we showed that adsorbing and covalently binding monoclonal antibodies to VAMS tips results in capturing of the target analyte in comparison to unmodified VAMS. Due to the ease of preparation, we moved forward using antibody adsorption to VAMS tip and optimized the procedure. Optimization of the procedure involved fine-tuning the antibody coupling step, washing process, and determining the optimal amount of antibody required, leading to a streamlined process with significant time savings up to two days. Recovery experiments demonstrate successful capture of the target analyte by the Affinity-VAMS, while matrix effects and stability assessments indicate no negative effects from serum matrix or storage conditions. Finally, quantitative analysis shows promising performance of the Affinity-VAMS in detecting different concentrations of the target analyte in the concentration range between 7.5 - 25 ng·mL−1. The calculated correlation factor was R2 of 0.9988 and limit of detection 2.5 ng·mL−1. The precision lays within the ICH guidelines for bioanalytical method validation. While this report is focused on the proof of concept of the Affinity-VAMS, our findings demonstrate the potential for the usage of modified VAMS in remote sampling and integrated sample processing, enhancing biomarker analysis in clinical and research settings.

A novel competitive color-tone change fluorescence immunochromatographic assay for the ultrasensitive detection of pesticide and veterinary drug residues

One important challenge faced by competitive immunoassay techniques is the inability to visually distinguish weak color changes in the T-line during the detection of trace analyte concentrations. In this study, we introduced multi-color fluorescence into the immunoassay system and developed a novel competitive dual-channel color-tone change fluorescent immunochromatographic assay (CFICA) for the visual and quantitative detection of kanamycin (KAN) and carbendazim (CBZ). At the same time, we have developed matching, portable fluorescence-reading equipment, which can analyse the spectral data of the RGB channel individually and can effectively solve the problems of the traditional single-fluorescence reader – large reading error and poor detection sensitivity. After optimization, our CFICA, combined with the corresponding instrument, achieved low limits of detection (LOD) for KAN and CBZ, as low as 1.98 and 12.82 pg/mL, respectively. We believe that this CFICA detection system, with its high accuracy, low error, and multi-color detection capabilities, holds tremendous potential for visual and multi-channel competitive point-of-care testing.

Bifenthrin Residues in Table Grapevine: Method Optimization, Dissipation and Removal of Residues in Grapes and Grape Leaves.

The QuEChERS method was adjusted to determine bifenthrin residues in grapes and grape leaves. Extraction and cleanup procedures were optimized to decrease co-extracted materials and enhance the detection of bifenthrin. The method was validated per the European Union (EU) Guidelines criteria. Accuracy ranged from 98.8% to 93.5% for grapes and grape leaves, respectively. Precision values were 5.5 and 6.4 (RSDr) and 7.4 and 6.7 (RSDR) for grapes and grape leaves, respectively. LOQs (the lowest spiking level) were 2 and 20 µg/kg for grapes and grape leaves, respectively. Linearity as determination coefficient (R2) values were 0.9997 and 0.9964 for grapes and grape leaves, respectively, in a matrix over 1-100 µg/L range of analyte concentration. This was very close to the value in the pure solvent (0.9999), showing the efficiency of the cleanup in removing the co-extracted and co-injected materials; the matrix effect was close to zero in both sample matrices. Dissipation of bifenthrin was studied in a supervised trial conducted in a grapevine field during the summer of 2023 at the recommended dose and double the dose. Dissipation factor k values were 0.1549 and 0.1672 (recommended dose) and 0.235 and 0.208 (double dose) for grapes and grape leaves, respectively. Pre-harvest interval (PHI) was calculated for the Maximum Residue Limit (MRL) values of the EU database. Residues of bifenthrin were removed effectively from grapes using simple washing with tap water in a laboratory study. Residues reached the MRL level of 0.3 mg/kg in both washing treatments, running or soaking in tap water treatments for 5 min. Removal from leaves did not decrease residue levels to the MRL in grape leaves.

Detection of Ovarian Cancer Biomarker Lysophosphatidic Acid Using a Label-Free Electrochemical Biosensor

Electrochemical biosensors are valued for their sensitivity and selectivity in detecting biological molecules. Having the advantage of generating signals that can be directly or indirectly proportional to the concentration of the target analyte, these biosensors can achieve specificity by utilizing a specific biorecognition surface designed to recognize the target molecule. Electrochemical biosensors have garnered substantial attention, as they can be used to fabricate compact, cost-effective devices, making them promising candidates for point-of-care testing (POCT) devices. This study introduces a label-free electrochemical biosensor employing a gold screen-printed electrode (SPE) to detect lysophosphatidic acid (LPA), a potential early ovarian cancer biomarker. We employed the gelsolin–actin system, previously introduced by our group, in combination with fluorescence spectrometry, as a biorecognition element to detect LPA. By immobilizing a gelsolin–actin complex on an SPE, we were able to quantify changes in current intensity using cyclic voltammetry and differential pulse voltammetry, which was directly proportional to the LPA concentration in the solution. Our results demonstrate the high sensitivity of the developed biosensor for detecting LPA in goat serum, with a limit of detection (LOD) and a limit of quantification (LOQ) of 0.9 µM and 2.76 µM, respectively, highlighting its potential as a promising tool for early-stage diagnosis of ovarian cancer.

Fabrication of rGO-decorated hBNNS hybrid nanocomposite via organic-inorganic interfacial chemistry for enhanced electrocatalytic detection of carcinoembryonic antigen.

Organic-inorganic hybrid nanocomposites (OIHN), with tailored surface chemistry, offer ultra-sensitive architecture capable of detecting ultra-low concentrations of target analytes with precision. In the present work, a novel nano-biosensor was fabricated, acquainting dynamic synergy of reduced graphene oxide (rGO) decorated hexagonal boron nitride nanosheets (hBNNS) for detection of carcinoembryonic antigen (CEA). Extensive spectroscopic and microscopic analyses confirmed the successful hydrothermal synthesis of cross-linked rGO-hBNNS nanocomposite. Uniform micro-electrodes of rGO-hBNNS onto pre-hydrolyzed ITO were obtained via electrophoretic deposition (EPD) technique at low DC potential (15V). Optimization of antibody incubation time, pH of supporting electrolyte, and immunoelectrode preparation was thoroughly investigated to enhance nano-biosensing efficacy. rGO-modified hBNNS demonstrated 29% boost in electrochemical performance over bare hBNNS, signifying remarkable electro-catalytic activity of nano-biosensor. The presence of multifunctional groups on the interface facilitated stable crosslinking chemistry, increased immobilization density, and enabled site-specific anchoring of Anti-CEA, resulting in improved binding affinity. The nano-biosensor demonstrated a remarkably low limit of detection of 5.47pg/mL (R2 = 0.99963), indicating exceptional sensitivity and accuracy in detecting CEA concentrations from 0 to 50ng/mL. The clinical evaluation confirmed its exceptional shelf life, minimal cross-reactivity, and robust recovery rates in human serum samples, thereby unraveling the potential for early, highly sensitive, and reliable CEA detection.

Plasmonic AgNPs reinforced flexible hydrogel Surface-Enhanced Raman scattering (SERS) sensor for in-situ detection of curved samples

In-situ detection of analytes on curved surfaces is a persistent and great challenge in the application of SERS technique. A hydrogel-based flexible SERS substrate demonstrates a unique charm for providing close contact to the real-sample surface but limited by its weak enhancement capability in the quantitative analysis. Herein, we report a reinforced hydrogel by reduction of plasmonic silver nanoparticles (AgNPs) on a PNIPAM membrane with the aid of polyvinylpyrrolidone (PVP) surfactant. The modification of AgNPs on PNIPAM endows the AgNPs/PNIPAM composite hydrogel with good mechanical properties and reinforced swelling property. Moreover, the AgNPs/PNIPAM hydrogel-based SERS sensor exhibits an enhanced SERS sensitivity as well as improved signal uniformity (RSD ＜10 %), and the detection concentration for pesticide molecules can be down to 10-9 M. Due to the fingerprint feature of SERS, multicomponent detection of pesticide mixtures was readily realized. In addition, the flexible AgNPs/PNIPAM hydrogel was successfully applied to the curved apple surface for SERS detection. Notably, it is capable of achieving qualitative and quantitative analyses of different pesticides, which has lower analytical concentrations than European Union (EU) standards, indicating the potential applications in rapid in-situ pesticide analysis.

Ratiometric nonfluorescent CRISPR assay utilizing Cas12a-induced plasmid supercoil relaxation

Most CRISPR-based biosensors rely on labeled reporter molecules and expensive equipment for signal readout. A recent approach quantifies analyte concentration by sizing λ DNA reporters via gel electrophoresis, providing a simple solution for label-free detection. Here, we report an alternative strategy for label-free CRISPR-Cas12a, which relies on Cas12a trans-nicking induced supercoil relaxation of dsDNA plasmid reporters to generate a robust and ratiometric readout. The ratiometric CRISPR (rCRISPR) measures the relative percentage of supercoiled plasmid DNA to the relaxed circular DNA by gel electrophoresis for more accurate target concentration quantification. This simple method is two orders of magnitude more sensitive than the typical fluorescent reporter. This self-referenced strategy solves the potential application limitations of previously demonstrated DNA sizing-based CRISPR-Dx without compromising the sensitivity. Finally, we demonstrated the applicability of rCRISPR for detecting various model DNA targets such as HPV 16 and real AAV samples, highlighting its feasibility for point-of-care CRISPR-Dx applications.

A gas sensor based on free-standing SWCNT film for selective recognition of toxic and flammable gases under thermal cycling protocols

The widespread adoption of e-nose devices based on chemiresistive materials has been hindered by issues related to sensor device complexity and reliability, specifically sensor drift, necessitating frequent recalibration and retraining of pattern recognition models. This study introduces a method for thermocycling a single sensor based on a free-standing network of single-walled carbon nanotubes (SWCNTs) to acquire signal patterns for selective analyte detection. Additionally, it employs a data filtering technique to compensate for the sensor drift. A free-standing SWCNT film, only a few nanometers thick, is thermally cycled via Joule heating between room temperature and 120 °C. Under these conditions, the sensitivity was tested towards NO2, H2S, and acetone vapors (10–25 ppm) in the mixture with dry air. Signal patterns produced through thermocycling were processed using CatBoost and LSTM algorithms. The accuracy of detection reached 90 % in the classification task, and the average root mean squared error of analyte concentration detection in the multioutput regression task was below 4 ppm. By combining original sensor design, thermocycling, signal filtering for drift compensation, and advanced pattern recognition models, this work contributes to overcoming the challenges in multivariate sensing systems, paving the way for practical applications of the more reliable chemiresistive sensors.

Inclusion of dilution quality control samples in quantitative LC-MS bioanalysis.

In LC-MS bioanalysis, sample dilution plays various roles, including bringing analyte concentrations within the validated/qualified dynamic range or alleviating matrix effect for accurate determination of the target analyte(s) in the intendedstudy samples. Adherence to health authority requirements, incorporating good dilution practices, and timely demonstration of dilution integrity whenever samples are diluted in an analytical run are essential to ensure the reliability of bioanalytical results.

Enhanced Cadmium Sensing in Fertilizer Samples using Zeolite-modified Graphite Electrode

The presence of heavy metals in fertilizers poses significant environmental and health risks, necessitating robust detection methods to ensure agricultural sustainability and food safety. This study focuses on synthesizing Na-P1 zeolite from coal fly ash and fumed silica wastes, employing it as a potent modifier in graphite electrodes to enhance the electrochemical detection of cadmium (II) in fertilizer samples. Through meticulous assessment using cyclic voltammetry (CV) in a potential window of −1.2 V to 0.5 V, square wave voltammetry (SWV) in a potential region of −1 V to 0.5 V, and electrochemical impedance spectroscopy (EIS) in a frequency ranging from 100 kHz to 10 mHz under open circuit potential polarization, the electrochemical performance of the zeolite-modified graphite electrode (ZGE) was evaluated. The optimization process involved fine-tuning various parameters such as paste composition, solution pH, scan rate, and analyte concentration. Real sample analysis confirmed the applicability of the method in fertilizer samples. Notably, in an HCl medium (pH = 1.0), the SWV oxidation peak of Cd(II) was observed at −0.56 V (vs SCE) with a deposition time of 20 s and a scan rate of 75 mV∙s−1. The ZGE exhibited a remarkable detection limit of 1 μM, a quantification limit of 5 μM, and a high sensitivity of 6.581 μA/μM.cm2 within a linear detection range of 10−3–10−6 M. These findings highlight the potential utility of Na-P1 zeolite in handheld analytic device manufacturing, offering promising applications in environmental monitoring, resource management, and water and soil resource remediation.

Utilization of Spontaneous Alkyne-Gold Self-Assembly Chemistry as an Alternative Method for Fabricating Electrochemical Aptamer-Based Sensors.

Electrochemical aptamer-based (E-AB) sensors are a promising class of biosensors which use structure-switching redox-labeled oligonucleotides (aptamers) codeposited with passivating alkanethiol monolayers on electrode surfaces to specifically bind and detect target analytes. Signaling in E-AB sensors is an outcome of aptamer conformational changes upon target binding, with the sequence of the aptamer imparting specificity toward the analyte of interest. The change in conformation translates to a change in electron transfer between the redox label attached to the aptamer and the underlying electrode and is related to analyte concentration, allowing specific electrochemical detection of nonelectroactive analytes. E-AB sensor measurements are reagentless with time resolutions of seconds or less and may be miniaturized into the submicron range. Traditionally these sensors are fabricated using thiol-on-gold chemistry. Here we present an alternate immobilization chemistry, gold-alkyne binding, which results in an increase in sensor lifetimes under ideal conditions by up to ∼100%. We find that gold-alkyne binding is spontaneous and supports efficient E-AB sensor signaling with analytical performance characteristics similar to those of thiol generated monolayers. The surface modification differs from gold-thiol binding only in the time and aptamer concentration required to achieve similar aptamer surface coverages. In addition, alkynated aptamers differ from their thiolated analogues only by their chemical handle for surface attachment, so any existing aptamers can be easily adapted to utilize this attachment strategy.

In Situ Formed Organic Ion-Associate Liquid-Phase Microextraction without Centrifugation from Aqueous Solutions Using Thymol Blue and Estrogens

In this study, we present a method for ion-associated liquid phase (IALP) separation and concentration of analytes from an aqueous matrix into an IALP formed in situ by the charge neutralization reaction of organic cations and anions, without centrifugation. The effects of various factors on the extraction efficiency and other parameters are investigated, whereas no instrumental stirring, such as vortexing or ultrasonics, is required because the solvent (IALP) is formed in situ. The organic cation and anion used are ethylhexyloxypropylammonium and dodecyl sulfate, respectively. The developed in situ IALP microextraction method for phase separation without centrifugation is tested using the thymol blue dye and several endocrine disruptors. The tested endocrine disruptors (bisphenol A, 17β-estradiol, 17α-ethinylestradiol, and estrone) are analyzed via high-performance liquid chromatography/fluorescence detection, with respective detection limits of 0.02, 0.02, 0.02, and 0.4 μg L−1, and the corresponding enrichment factor ranging from 47 to 71. This IALP microextraction method can be used to separate and concentrate environmental water samples of different matrices. The employed IALP is fast and easy to use, enables an approximately 100-fold analyte concentration, and has a high affinity for estrogens, thus holding promise for the separation, concentration, and quantitation of diverse trace analytes.

Exploring the potential of multiomics liquid biopsy testing in the clinical setting of lung cancer.

The transformative role of artificial intelligence (AI) and multiomics could enhance the diagnostic and prognostic capabilities of liquid biopsy (LB) for lung cancer (LC). Despite advances, the transition from tissue biopsies to more sophisticated, non-invasive methods like LB has been impeded by challenges such as the heterogeneity of biomarkers and the low concentration of tumour-related analytes. The advent of multiomics - enabled by deep learning algorithms - offers a solution by allowing the simultaneous analysis of various analytes across multiple biological fluids, presenting a paradigm shift in cancer diagnostics. Through multi-marker, multi-analyte and multi-source approaches, this review showcases how AI and multiomics are identifying clinically valuable biomarker combinations that correlate with patients' health statuses. However, the path towards clinical implementation is fraught with challenges, including study reproducibility and lack of methodological standardization, thus necessitating urgent solutions to solve these common issues.