Search

Large clinical laboratories often rely on multiple chemistry analyzers. However, when a new analyzer is introduced, the laboratory must establish whether the old and new methods are comparable and can be used interchangeably. In this study, we compared the newly introduced Atellica CH930 chemistry analyzer with the already established Architect ci4100 and Cobas 6000 c501 from our laboratory. Patient samples were randomly selected from daily routine testing and a total of 22 analytes were investigated. Total error (TEobs) between test (Atellica) and comparative (Architect and Cobas) methods was calculated at relevant medical decision levels (MDL). For demonstrative purposes, the assessment of method comparability was based on three different criteria: allowable total error (TEa) derived from biological variation (BV), CLIA proficiency testing criteria for acceptable analytical performance, and CLIA-calculated Sigma metrics. These sets of analytical performance specifications were also compared, and their strengths and limitations are discussed in this paper. Performance of Atellica CH930 against Architect ci4100 was acceptable or nearly acceptable at 82%, 95%, and 64% of the 22 investigated MDLs across 9 analytes, according to BV-TEa, CLIA-TEa, and CLIA-calculated Sigma metrics, respectively. Similarly, performance of Atellica CH930 against Cobas 6000 c501 was acceptable or nearly acceptable at 61%, 93%, and 63% of the 54 investigated MDLs across 22 analytes, according to BV-TEa, CLIATEa, and CLIA-calculated Sigma metrics, respectively. However, method comparability should not be evaluated by a “one size fits all” approach as some analytes require different criteria of acceptability, ideally based on medically allowable error and clinical outcome.

Hospital Pharmacy, 57 (2), ISSN:0018-5787, ISSN:1945-1253

The objective of this study consists of being able to develop a precise, reliable, easy, cheap and quick method to identify and quantify the presence of pesticide metabolites and their parents in human urine. In order to reach our purpose we selected the pesticides and their metabolites with intended uses on permanent crops such as orchards and vineyard. The activity planning started with the identification of the target list carried out by UHPLC-MS/MS and GC-MS/MS, succeeded by several tests oriented to determine the best sample treatment having recourse to instrumental analysis in the range 5-100 ng/mL. Several purifications were also investigated combining different adsorbents (PSA, EMR-lipid and final polish pouch). The use of formic acid during the extraction step has no impact on the recoveries, whereas the PSA adsorbent in the cleanup step negatively affects the results for all investigated metabolites. Any substantial differences were not observed in urine matrix for parent compounds achieving recoveries higher than 80% and RSD less than 20%. The final polish in combination or not with Enhanced Matrix Removal EMR-lipid did not show statistically significant difference in term of trueness and precision for both metabolites and parents, as evaluated by one-way ANOVA. The 3-OH THPI was the most critical compound with not acceptable results for linearity, trueness and precision.

The aim of the present study was to quantify a large number of analytes including opioids, stimulants, benzodiazepines, z-drugs, antidepressants and neuroleptics within a single sample workup followed by a single analytical measurement. Expected drug concentrations in hair are strongly substance dependent. Therefore, three different calibration ranges were implemented: 0.5 to 600 pg/mg (group 1), 10 to 12,000 pg/mg (group 2) and 50 to 60,000 pg/mg (group 3). In order to avoid saturation effects, different strategies were applied for selected transitions including the use of parent mass ions containing one or two 13C-isotopes and detuning of the declustering potential and/or collision energy. Drugs were extracted from pulverized hair by a two-step extraction protocol and measured by liquid chromatrography--tandem mass spectrometry (LC--MS-MS) using Scheduled MRM™ Algorithm Pro. In total, 275 MRM transitions including 43 deuterated standards were measured. The method has been fully validated according to international guidelines. A MultiQuant™ software based tool for task-oriented data evaluation was established, which allows extracting selected information from the measured data sets. The matrix effects and recoveries were within the allowed ranges for the majority of the analytes. The lower limits of quantification (LLOQs) were for ∼72% of the analytes in the low-pg/mg range (0.5–5 pg/mg) and for ∼24% of the analytes between 10 and 50 pg/mg. These LLOQs considered cut-offs by the Society of Hair Testing (SoHT), if recommended. The herein established multi-analyte approach meets the specific requirements of forensic hair testing and can be used for the rapid and robust measurement of a wide range of psychoactive substances. The analyte-specific wide concentration ranges open up a wide field of applications.

Clinical time series imputation is recognized as an essential task in clinical data analytics. Most models rely either on strong assumptions regarding the underlying data-generation process or on preservation of only local properties without effective consideration of global dependencies. To advance the state of the art in clinical time series imputation, we participated in the 2019 ICHI Data Analytics Challenge on Missing Data Imputation (DACMI). In this paper, we present our proposed model: Context-Aware Time Series Imputation (CATSI), a novel framework based on a bidirectional LSTM in which patients' health states are explicitly captured by learning a "global context vector" from the entire clinical time series. The imputations are then produced with reference to the global context vector. We also incorporate a cross-feature imputation component to explore the complex feature correlations. Empirical evaluations demonstrate that CATSI obtains a normalized root mean square deviation (nRMSD) of 0.1998, which is 10.6% better than that of state-of-the-art models. Further experiments on consecutive missing datasets also illustrate the effectiveness of incorporating the global context in the generation of accurate imputations.

Background Anti-mitochondrial autoantibodies (AMA) detected by indirect immunofluorescence (IIF) on rodent tissues are the diagnostic marker of primary biliary cholangitis (PBC). However, up to 15% of patients with PBC are AMA-negative by IIF. In the effort to close the serological gap and improve the diagnostic sensitivity of PBC testing, recently, novel autoantibodies specific for PBC, such as kelch-like 12 (KLHL12, KLp epitope) and hexokinase 1 (HK1) have been described. In this study, we evaluated the autoantibody profile in a large cohort of PBC patients and in patients with other liver disease, including anti-HK1 and anti-KLp autoantibodies. Methods Sera of 194 PBC patients (126 AMA-IIF-positive and 68 AMA-IIF-negative) and 138 disease controls were tested for a panel of PBC-specific antibodies (MIT3, sp100, gp210, HK1, KLp) using a new automated particle-based multi-analyte technology (PMAT) assay on the Aptiva instrument (Inova). Results Selecting a cutoff yielding a specificity of >95% for all the markers, the sensitivity for anti-MIT3, anti-sp100, anti-gp210, anti-HK1 and anti-KLp in the PBC AMA-IIF-negative cohort was 20.6%, 16.2%, 23.5%, 22.0%, 17.6 and 13.2%, respectively. Six out of the 68 (8.8%) AMA-IIF negative sera were positive for anti-HK1 or anti-KLp alone. Using these new markers in addition to anti-MIT3, anti-sp100 and anti-gp210, the overall sensitivity in this cohort of AMA-IIF-negative patients increased from 53% to 61.8%, reducing the serological gap in AMA-negative PBC patients. Conclusions PBC antibody profiling, made possible by the new Aptiva-PMAT technology, allows recognition of a higher number of AMA-negative PBC patients than conventional immunoassays and may represent a useful tool to evaluate the prognostic significance of autoantibody association in PBC patients.

A multifunctional chemical neural probe fabrication process exploiting PDMS thin-film transfer to incorporate a microfluidic channel onto a silicon-based microelectrode array (MEA) platform, and enzyme microstamping to provide multi-analyte detection is described. The Si/PDMS hybrid chemtrode, modified with a nano-based on-probe IrOx reference electrode, was validated in brain phantoms and in rat brain.

Lab on a chip 22(2), 225-239 (2022). doi:10.1039/d1lc00689d, Published by RSC, Cambridge

An analytical method was developed and validated for the analysis of 32 halogenated flame retardants (HFRs), including 13 polybrominated diphenyl ethers (PBDEs), 9 dechlorane-related compounds (DRCs) and 10 of the so-called alternative BFRs in food samples of animal origin. Gas chromatography (GC) coupled with magnetic sector high resolution mass spectrometry (HRMS) was used for the instrumental analysis. Intralaboratory validation of the developed method was performed in terms of recovery, repeatability, linear calibration ranges, instrumental and method limits of quantitation (i-LOQ and m-LOQ). Where possible, trueness was verified by the analysis of reference materials (RMs). For analytes with available isotopically labeled surrogates, recoveries in the range of 70–120% and repeatability rates below 20% were observed, while for compounds quantitated using absolute calibration the values of recovery ranged from 59 to 153% and the repeatability in terms of RSDs was in the range of 1–26%. The values measured for the four analyzed RMs agreed with the provided consensus values, revealing that the recovery of reference concentrations for compounds with assigned consensus values was in 72–119% range. The elaborated method met the sensitivity criteria according to the Commission Recommendation, 2014/118/EU on the monitoring of BFRs in food products. The developed method was successfully applied for the analysis of numerous food samples. The analyses revealed ubiquitous presence of PBDEs and the majority of DRCs in the analyzed samples, while alternative BFRs were detected only occasionally.

Recently, ultrasensitive detection and multi-guest sensing have received extensive attention due to their high sensitivity and efficiency. Herein, we report a novel approach to achieve ultrasensitive detection of multi-analyte. This approach is concluded as "rationally introduce Aggregation-Induced Emission (AIE) into chemosensor". According to this approach, by rationally introducing self-assembly moiety, the obtained chemosensor DNS could serve as a novel AIEgen and show strong AIE in DMSO/H2O (water fraction 80%) binary solution. Interestingly, a simple fluorescent sensor array based on the DNS has been developed. This sensor array could selectively sense Fe3+, Al3+, H2PO4- and L-Arg in water solution. More importantly, this sensor array shows ultrasensitive detection for Fe3+, Al3+ and L-Arg. The LODs of the sensor array for Fe3+, Al3+ and L-Arg are in the range of 3.54×10-9M to 9.42×10-9M. Moreover, H2PO4- could realize the reversible detection of Fe3+ in the DMSO/H2O (water fraction 80%) solution. Meanwhile, DNS-based test papers and thin films were prepared, which could serve as test kits for convenient detection Fe3+, Al3+, and L-Arg in water. In addition, they could also act as efficient erasable fluorescent display materials.

In contrast to the classical design of a probe with one binding site to target one specific analyte, probes with multiple interaction sites or, alternatively, with single sites promoting tandem reactions to target one or multiple analytes, have been developed. They have been used in addressing the inherent challenges of selective targeting in the presence of structurally similar compounds and in complex matrices, as well as the visualization of the in vivo interaction or crosstalk between the analytes. Examples of analytes include reactive sulfur species, reactive oxygen species, nucleotides and enzymes. This review focuses on recent innovations in probe design, detection mechanisms and the investigation of biological processes. The vision is to promote the ongoing development of fluorescent probes to enable deeper insight into the physiology of bioactive analytes.

The performance characteristics of a multi-analyte method for the determination of all 10 carotenoids authorised as feed additives within the EU were assessed via an interlaboratory study. The analytical method is based on reversed phase high performance liquid chromatography (RP-HPLC) coupled to an optical detector set at 410 nm. The analysis is particularly challenging due to the presence of various stereoisomers of each carotenoid, and the use of these compounds via natural or synthetic formulations, requiring a special sample preparation. EU regulations specifying the conditions of use set legal limits for these substances in compound feedingstuffs ranging from 6 mg kg

Among &ldquo, extra-criteria&rdquo, antiphospholipid antibodies (aPL), anti-phosphatidylserine/prothrombin (aPS/PT) antibodies, are considered a part of risk assessment strategies when investigating patients suspected of having antiphospholipid syndrome (APS). aPL detection is currently performed by solid-phase assays to identify anti-cardiolipin (aCL), anti-&beta, 2glycoprotein I (a&beta, 2GPI) and aPS/PT antibodies, but new techniques are emerging. Among these, particle-based multi-analyte technology (PMAT), which allows the full automation and simultaneous digital detection of autoantibodies and proteins, including IgG, IgA and IgM isotypes of aCL, a&beta, 2GPI and aPS/PT. The aim of this study was to investigate the agreement of aPS/PT testing between enzyme-linked immunosorbent assay (ELISA) and the PMAT platform. A total of 94 patients were enrolled in the study, including 71 patients with confirmed APS and 23 &ldquo, aPL carriers&rdquo, aPS/PT IgG showed a moderate binomial agreement between ELISA and PMAT (k = 0.57, 95% CI 0.45&ndash, 0.75), and aPS/PT IgM showed a moderate agreement (k = 0.60, 95% CI 0.45&ndash, 0.75). Moreover, when considering the continuous agreement, both aPS/PT IgG and IgM showed a statistically significant correlation between ELISA and PMAT (Spearman&rsquo, s correlation = 0.69, p &lt, 0.001 and 0.72, p &lt, 0.001, respectively). This study demonstrates that PMAT technology is a reliable method for aPS/PT IgG and IgM testing when compared to the available commercial ELISA kit.

Cell analysis by optochemical sensing represents large and important niche in life and biomedical sciences. We present advanced multi-modal, multi-analyte sensing platform and dedicated materials for cell analysis based on the substituted phosphorescent Pt(II)- or Pd(II)-porphyrin indicator dyes bearing dual O2 and pH sensing functionality (MePor-SB). The study includes screening of the different host matrices for the sensor, synthesis and evaluation of new MePor-SB derivatives with altered protonation behaviour, development of the ratiometric version of the pH sensor, assessment of photoluminescent signal enhancement options, deposition of sensor coatings on common cell analysis substrates and their demonstration of sensor performance in Oxygen Consumption Rate (OCR) and Extracellular Acidification (ECA) measurements with relevant cell models. The main outcomes include the elaboration of the structure-function relationships for this biosensor system, development of the self-referenced tandem O2/pH and OCR/ECA sensing system which enables calibration-free operation, demonstration of the sensor operation on common plastic substrates in cell analysis, benchmarking against the existing platforms and real-life experiments with cells. This new sensing platform shows potential for wide practical use.

The diagnosis of Central Nervous System (CNS) malignancies such as Gliomas in individuals presenting with Intracranial Space Occupying Lesions (ICSOL) is based on histopathological examination (HPE) of tumor tissue obtained by an invasive brain biopsy. However, brain biopsies are resource intensive and are associated with procedural risks such as haemorrhage, morbidity and mortality. The present study evaluated a non-invasive approach for diagnosis of CNS-M in symptomatic individuals based on evaluation of circulating tumor analytes in peripheral blood. The non-invasive multi-platform approach for diagnosis of CNS-M included Immunocytochemistry (ICC) profiling and Fluorescence in situ Hybridization (FISH) of Circulating Tumor Cells (CTCs) and Digital Droplet PCR (ddPCR) of cell-free tumor DNA (ctDNA) and exosomal mRNA. Performance characteristics of each platform were evaluated using blood and tissue samples from 445 individuals including 227 known cases of CNS-M, 47 known cases of benign CNS conditions (CNS-B), 141 known cases of other cancers with brain metastases (OTH-M) and 30 asymptomatic individuals (ASYM). In a set of 37 samples from individuals with radiological ICSOL, suspected of malignancy (CNS-S) complete diagnostic work-up was performed with ICC, FISH and ddPCR. Glial CTCs were detected in 88.8% of 227 CNS-M and undetectable in 89.4% of 47 CNS-B or 100% of 141 OTH-M, indicating high sensitivity and specificity, respectively. The multi-analyte approach discerned CNS-M from CNS-B as well as OTH-M with 91.7% accuracy and accurately inferred lineage in 84.6% of cases. This non-invasive multi-analyte approach can diagnose CNS-M with an accuracy not inferior to standard HPE, can substitute invasive biopsies in most cases and is particularly helpful in cases where a biopsy is not viable.

Background LIQUID IMPACT (CTRI/2019/02/017548) is a single arm, open label, phase II/III study to evaluate the feasibility of providing therapeutic guidance in cancers based on non-invasive interrogation of circulating tumor analytes in peripheral blood (Encyclopedic Liquid Biopsy: eLB). The study enrolled patients with solid organ cancers where the disease had progressed following systemic therapy failure, where no (further) viable standard of care (SoC) therapy options were available, and where invasive biopsies to obtain tumor tissue (for molecular profiling) were contraindicated. Methods Encyclopedic Liquid Biopsy (eLB) interrogated gene alterations in cell-free tumor DNA (ctDNA), and differentially expressed genes in exosomal mRNA. eLB also evaluated Circulating Tumor Associated Cells for expression of therapeutically relevant cell-surface signaling receptors as well as the chemoresistance profile towards systemic anticancer agents. Patients who received personalized combination therapy regimens based on eLB findings were evaluated radiologically to determine response to treatment, Objective Response Rate (ORR) and Quality of Life (QoL). Results At the time of submission of this manuscript, Partial Response (PR) was observed in 14 of 43 patients evaluable per protocol (ORR = 32.6%). Majority of patients reported stable to improved QoL. Conclusion The present study demonstrated that refractory cancers have latent vulnerabilities which can be identified via non-invasive eLB to design personalized label- and organ-agnostic treatment regimens to yield meaningful treatment benefit. Trial registration Clinical Trial Registry – India, CTRI/2019/02/017548 [Registered on: 02/08/2019] - http://ctri.nic.in/Clinicaltrials/pdf_generate.php?trialid=31265&EncHid=&modid=&compid=%27,%2731265det%27; Trial Registered Prospectively.

Novel androgen receptor (AR) signaling inhibitors have improved the treatment of castration-resistant prostate cancer (CRPC). Nonetheless, the effect of these drugs is often time-limited and eventually most patients become resistant due to various AR alterations. Although liquid biopsy approaches are powerful tools for early detection of such therapy resistances, most assays investigate only a single resistance mechanism. In combination with the typically low abundance of circulating biomarkers, liquid biopsy assays are therefore informative only in a subset of patients. In this pilot study, we aimed to increase overall sensitivity for tumor-related information by combining three liquid biopsy approaches into a multi-analyte approach. In a cohort of 19 CRPC patients, we (1) enumerated and characterized circulating tumor cells (CTCs) by mRNA-based in situ padlock probe analysis, (2) used RT-qPCR to detect cancer-associated transcripts (e.g., AR and AR-splice variant 7) in lysed whole blood, and (3) conducted shallow whole-genome plasma sequencing to detect AR amplification. Although 44&ndash, 53% of patient samples were informative for each assay, a combination of all three approaches led to improved diagnostic sensitivity, providing tumor-related information in 89% of patients. Additionally, distinct resistance mechanisms co-occurred in two patients, further reinforcing the implementation of multi-analyte liquid biopsy approaches.

Quality estimation of reservoir fluid compositions from optical sensor measurements (OPTs) is crucial for real-time downhole fluid analysis. Conventional workflow, which performs multiple single-analyte predictions with neural networks (NNs), often suffers the issue of mass balance in estimated outputs. In this study, single-analyte fluid characterization (SAFC) is compared with a novel multi-analyte fluid characterization (MAFC) method. The investigation aims to evaluate whether the new method can maximize the balance of the density concentrations of fluid compositions and provide self-consistent solutions to support early decision making on reservoir exploitation and production optimization. As an inversion problem, fluid characterization in this paper is accomplished in two stages using NNs. The first stage converts actual sensor measurements into synthetic optical responses. After the optical data transformation is completed, then fluid characterization at the second stage is applied using synthetic optical data inputs. The combination of optical data transformation and fluid characterization networks forms a concatenated optical computing network (COCN) for downhole fluid analysis. The performance evaluation is conducted on the calibration database first, followed by comprehensive testing assessment using simulation data and laboratory measurement data. Fluid characterization networks developed on a large database pertain to low uncertainty for both multi-analyte and single-analyte calibrations. SAFC networks allow for selecting analyte-specific network inputs and manipulating the network performance under its own connecting parameter space. However, the inherent data relationship and constraints among the fluid compositions and properties are not utilized to calibrate individual models. This limitation often leads to inconsistent compositional predictions on the new data and hence requires post-processing of output data from multiple single-analyte networks. MAFC networks, in comparison, have constraints of fluid compositions built into training outputs. By minimizing overall training error on all compositional outputs, MAFC networks structurally ensure the self-consistent predictions on analyte density concentrations. Nevertheless, sharing network parameters in the hidden layers necessitates the use of more complex MAFC network structures to improve overall prediction accuracy. The quality of optical data transformation, which affects all fluid compositional outputs with less flexibility in input selection, can present challenges during MAFC network application. Conventional optical data transformation networks calibrated on a small number of reference fluids are capable of supporting sensor-based fluid characterization but cannot justify the robust mapping for sensor-independent MAFC networks because of the limitation associated with sparse-data-based transformation model development. New transformation networks, which facilitate fluid analysis with generic optical inputs, are built through two-directional progressive calibration to improve data mapping. The resulting reverse and forward transformation networks can be optimized using measurement and simulation data and validated in real-time signal processing. Applying reverse and forward transformation networks alternatively, for example, can help determine the degree of matching between simulated and measured optical sensor data. Using the quality of matching as a performance index can also enhance uncertainty assessment of predictions from fluid characterization networks. It has been demonstrated that the novel transformation networks developed during this study provide more robust optical sensor data mapping and improve predictions for both MAFC and SAFC networks.

Enormous economic losses and reported cases of bird-to-human transmission alert us the importance of AIVs surveillance in natural foci. However, the limited multiplexing capacity of PCR or real-time PCR method made AIVs surveillance insufficient, costly and labor intensive. In this study, we developed a multi-analyte suspension assay (MASA) to detect AIVs subtypes based on Luminex xMAP technology. With this MASA, 7 HA and 5 NA subtypes could be identified in a single reaction. The evaluation data showed that these subtype-specific amplified primers had high specificity and the coverage of each primer pairs ranged from 82% to 97%. Our studies provide a rapid and economical method for AIVs surveillance of natural foci.

6,6′-((1E,1′E)-((2E,2′E)-((2-hydroxy-5-methyl-1,3-phenylene)bis(methanylylidene))bis(hydrazine-2,1-diylidene))bis(methanylylidene))bis(3-methoxyphenol). (H3L) is a multi-responsive vanilinyl-p-cresol diformyl Schiff base fluorescent chemosensor for Zn2+ (λem, 545 nm), Cd2+ (λem, 560 nm) (both in 9 : 1 (v/v) DMSO–water), and I− (λem, 630 nm in THF). The probe (H3L) is spectroscopically characterised and the chemosensing mechanism is demonstrated through 1H NMR, ESI-MS, absorption and luminescence spectral data. The most promising advantage of the probe (H3L) is its application in the one-pot detection of Zn2+ and Cd2+ using excitation at the same wavelength (λex, 482 nm) while highly intense emission appears at two different wavelengths. A detection kit is designed for drinking water analysis and has been checked to measure the quality of potable water in the locality. The sensor is also applied to construct an INHIBIT logic gate. Density Functional Theory (DFT) calculations are used to optimize the structure and the electronic properties are correlated with the experimental results.

A novel organic gelator (WJ) based on benzimidazole and acylhydrazone naphthol moities has been designed and synthesized. The organic gelator (WJ) could form a stable organogel (WJG) with strong aggregation-induced emission (AIE). Interestingly, the WJG shows multi-stimuli-response for many analytes such as CN−, Al3+ and Fe3+ and L-Cys. Therefore, a multi-analyte sensor array based on WJG has been successfully developed. The WJG presents selective fluorescent and colorimetric response for CN−. Meanwhile, the WJG could selectively identify Fe3+ and Al3+ in the gel state. With the addition of Fe3+ the yellow-green AIE of WJG was quenched. In addition, the AIE of WJG could be selectively recovered by adding L-Cys. So the AIE presents an “on–off–on” type by alternatively adding Fe3+ and L-Cys. Moreover, upon the addition of Al3+, the yellow-green AIE of WJG shows a blue shift and changes to blue. The detection limits of the sensor array for CN−, Al3+ and Fe3+ are 3.02 × 10−6 M, 5.78 × 10−8 M, and 3.81 × 10−9 M, respectively. The WJG could act as a multi-analyte detection and fluorescent display material.

Enzyme Linked Immunosorbent Assay (ELISA) is a standard assay that has been used widely to validate the presence of analyte in the solution. With the advancement of ELISA, different strategies have shown and became a suitable immunoassay for a wide range of analytes. Herein, we attempted to provide additional evidence with ELISA, to show its suitability for multi-analyte detection. To demonstrate, three clinically relevant targets have been chosen, which include 16kDa protein from Mycobacterium tuberculosis, human blood clotting Factor IXa and a tumour marker Squamous Cell Carcinoma antigen. Indeed, we adapted the routine steps from the conventional ELISA to validate the occurrence of analytes both in homogeneous and heterogeneous solutions. With the homogeneous and heterogeneous solutions, we could attain the sensitivity of 2, 8 and 1nM for the targets 16kDa protein, FIXa and SSC antigen, respectively. Further, the specific multi-analyte validations were evidenced with the similar sensitivities in the presence of human serum. ELISA assay in this study has proven its applicability for the genuine multiple target validation in the heterogeneous solution, can be followed for other target validations.

Label-free simultaneous detection of Alzheimer’s disease (AD) specific biomarkers Aβ40 and Aβ42 peptides on a single platform using polypyrrole nanoparticle-based chemiresistive biosensors is reported here. The proposed interdigitated-microelectrode based inexpensive multisensor-platform can concurrently detect Aβ40 and Aβ42 in spiked-plasma in the range of 10-14 – 10-6 g/mL (with LoDs being 5.71 and 9.09 fg/mL, respectively), enabling the estimation of diagnostically significant Aβ42/Aβ40 ratio. A detailed study has been undertaken here to record the individual sensor responses against spiked-plasma samples with varying amounts and proportions of the two target peptides, towards enabling disease-progression monitoring using the Aβ-ratio. As compared to the existing cost-ineffective brain-imaging techniques such as PET and MRI, and the high-risk CSF based invasive AD biomarkers detecting procedures, the proposed approach offers a viable alternative for affordable point-of-care AD diagnostics, with possible usage in performance evaluation of therapeutic drugs. Towards point-of-care applications, the portable readout used in this work was conjugated with an android-based mobile app for data-acquisition and analysis.

Major types of internal can coatings used for food and beverages are made from synthetic polymers known as epoxy-based resins, mainly based on bisphenol A diglycidyl ether (BADGE). The migration of components from coatings to food is a concern for food safety. A multiresidue method was developed for the identification and quantification of six bisphenols, BADGE and its derivatives, and cyclo-di-BADGE in sixteen canned food samples based on HPLC-FLD. The method developed showed excellent validation data with an adequate linearity, low detection levels, good repeatability and acceptable recoveries. Confirmation of the obtained results was made by LC–MS/MS. The exposure of the adult population to these compounds through the consumption of canned food was assessed. In general, the results suggested a low dietary exposure to this type of compounds (0.003 to 0.985 μg/kg bw/day) with values lower than the established tolerable day intake (TDI). The highest mean concentration was observed for cyclo-di-BADGE in a sample of pickled mussels SI

Aim: ImmunoPCR technology combines the advantages of specificity and robustness of a ligand binding assay with the amplification potential of PCR. We describe through three case studies a plug-and-play immuno polymerase chain reaction (iPCR) technique to measure biomolecules. Results: Case Study 1 demonstrated feasibility of measurement of IgG1 in cerebrospinal fluid at the desired level of sensitivity with minimal cost and timelines of clinical assay implementation. Case Study 2 translated the iPCR protocol to measure multiple IgG1 analytes in cerebrospinal fluid. Case Study 3 demonstrated broad applicability of the technique to yet another analyte IL-6. Conclusion: The advantages of our iPCR approach were: lack of reliance on a single vendor for technology platform/software, minimal reliance on proprietary reagents and reduced method development times and cost.

In postmortem toxicology, fast methods can provide a triage to avoid unnecessary autopsies. Usually, this requires multiple qualitative and quantitative analytical methods. The aim of the present study was to develop a postmortem LC-QTOF method for simultaneous screening and quantitation using easy sample preparation and reduced alternative calibration models. Hence, a method for 24 highly relevant substances in forensic toxicology was fully validated using the following calibration models: one-point external, one-point internal via corresponding deuterated standards, multi-point external daily calibration, and multi-point external weekly calibration. Two hundred microliters of postmortem blood were spiked with internal deuterated standard mixture and extracted by acetonitrile protein precipitation. Analysis was performed on a Sciex 6600 QTOF instrument with ESI+ mode using data-independent acquisition (DIA) namely sequential window acquisition of all theoretical mass spectra (SWATH). Validation of the different calibration models included selectivity, autosampler stability, recovery, matrix effects, accuracy, and precision for 24 substances. In addition, corresponding deuterated analogs of 52 substances were included to the internal standard mix for semi-quantitative concentration assessment. The simple protein precipitation provided recoveries higher than 55 and 75% for all analytes at low and high concentrations, respectively. Accuracy and precision criteria (bias and imprecision ± 15 and ± 20% near the limit of quantitation) were fulfilled by the different calibration models for most analytes. The validated method was successfully applied to more than 100 authentic postmortem samples and 3 proficiency tests. Furthermore, the one-point internal calibration via corresponding deuterated standard proved to be a considerably time saving technique for 76 analytes. Graphical abstract One-point and multi-point calibration and the resulting beta-tolerance intervals from method validation.

Background We describe the analytical validation of an assay panel intended to assist clinicians with the diagnosis of systemic lupus erythematosus (SLE). The multi-analyte panel includes quantitative assessment of complement activation and measurement of autoantibodies. Methods The levels of the complement split product C4d bound to erythrocytes (EC4d) and B-lymphocytes (BC4d) (expressed as mean fluorescence intensity [MFI]) are measured by quantitative flow cytometry, while autoantibodies (inclusive of antinuclear and anti-double stranded DNA antibodies) are determined by immunoassays. Results of the multi-analyte panel are reported as positive or negative based on a 2-tiered index score. Post-phlebotomy stability of EC4d and BC4d in EDTA-anticoagulated blood is determined using specimens collected from patients with SLE and normal donors. Three-level C4 coated positive beads are run daily as controls. Analytical validity is reported using intra-day and inter-day coefficient of variation (CV). Results EC4d and BC4d are stable for 2 days at ambient temperature and for 4 days at 4 °C post-phlebotomy. Median intra-day and inter-day CV range from 2.9% to 7.8% (n = 30) and 7.3% to 12.4% (n = 66), respectively. The 2-tiered index score is reproducible over 4 consecutive days upon storage of blood at 4 °C. A total of 2,888 three-level quality control data were collected from 6 flow cytometers with an overall failure rate below 3%. Median EC4d level is 6 net MFI (Interquartile [IQ] range 4-9 net MFI) and median BC4d is 18 net MFI (IQ range 13-27 net MFI) among 86,852 specimens submitted for testing. The incidence of 2-tiered positive test results is 13.4%. Conclusion We have established the analytical validity of a multi-analyte assay panel for SLE.

Biosensors combine the sensitivity of detection technology with the specificity of a designated biological entity. Owing to their specificity and sensitivity, biosensors are applied for sensing and monitoring of different diseases. Simultaneous sensing of myriad of biomarkers in different diseases at the early stages is swiftly finding its way towards disease's hallmarks, even though the biological contexts are complex matrices with possible cross-reactivity of restrained biomolecules. Electrochemical biosensors are considered as simple and cost-effective methods, which make the concurrent detection of multiple biomarkers plausible for ultimate diagnosis of diseases in clinic. Simultaneous sensing of multiple biomarkers by electrochemical techniques can be achieved through either multi-label or multi-electrode approaches, which can be implemented as miniaturized screen-printed or even lab-on-a-chip systems. Here, we reviewed literature (2000–2016) and provided a comprehensive insight on various biosensing platforms, articulating the most recent advancements in each type of biosensors applied for the detection of biomolecules.

3D plasmonic colloidosomes are superior SERS sensors owing to their high sensitivity and excellent tolerance to laser misalignment. Herein, we incorporate plasmonic colloidosomes in a microfluidic channel for online SERS detection. Our method resolves the poor signal reproducibility and inter-sample contamination in the existing online SERS platforms. Our flow system offers rapid and continuous online detection of 20 samples in less than 5 min with excellent signal reproducibility. The isolated colloidosomes prevent cross-sample and channel contamination, allowing accurate quantification of samples over a concentration range of five orders of magnitude. Our system demonstrates high-resolution multiplex detection with fully preserved signal and Raman features of individual analytes in a mixture. High-throughput multi-assay analysis is performed, which highlights that our system is capable of rapid identification and quantification of a sequence of samples containing various analytes and concentrations.

Aim: Immune-checkpoint inhibitors are presumed to break down the tolerogenic state of immune cells by activating T-lymphocytes that release cytokines and enhance effector cell function for elimination of tumors. Measurement of cytokines is being pursued for better understanding of the mechanism of action of immune-checkpoint inhibitors, as well as to identify potential predictive biomarkers. Results: In this study, we show bioanalytical qualification of cytokine assays in plasma on a novel multi-analyte immunoassay platform, Simple Plex™. The qualified assays exhibited excellent sensitivity as evidenced by measurement of all samples within the quantifiable range. The accuracy and precision were 80–120% and 10%, respectively. Conclusion: The qualified assays will be useful in assessing mechanism of action cancer immunotherapies.

The clinical use of biomarker assays to identify cancers, at a sufficiently early enough stage to enable a surgical cure, remains the “Holy Grail” of cancer diagnostics (1). Progress in various bio-assays, especially with liquid biopsies using molecular genetic markers (2), has excited the research community although their adoption in routine clinical practice remains elusive.

An incident of sartan medicine contamination was notified by Europe in June 2018. The contaminant was identified as a probable carcinogenic nitrosamine and the recalls of sartan medicines were soon made. Since then, more nitrosamine contaminants in sartan medicines were reported. To broaden the applicability and variety in nitrosamine determination, a multi-analyte method is required. In this study, a feasible and sensitive multi-analyte LC-MS/MS method for determination of 12 nitrosamines in sartans was established, where the active pharmaceutical ingredients and final products merchandised in Taiwan were also examined. Chromatographic separation was achieved on an Xselect

The development of microfluidic sensors as cost-effective strategies for environmental monitoring has been a primary goal for the platform since the 1980s. This paper outlines the lessons learned, during the designing and testing of biochemical assay protocols on a Lab-on-a-Disc (LOAD), using "MARIne environmental in-situ Assessment and monitoring tool BOX" (MARIABOX) project. Two novel platforms were produced in the MARIABOX project, with the latter mostly falling outside the scope of this study: A centrifugal microfluidic platform which would perform on-disc biochemical assays, and a deployable ‘Smart Buoy’ which would manage the storage, performance and biosensor detection of the centrifugal microfluidic platform. The technical challenge of the project was an -in-situ system and the monitoring of eight separate analytes including microcystin, saxitoxin, domoic acid, azaspiracid, perfluorooctanesulfonic acid, naphthalene, camphechlor and heavy metal presence. This paper highlights the concurrent and collaborative strategy used by the 14 international partners of the MARIABOX project, required to achieve the 4-year development target.

Information on the occurrence and endocrine potencies of analogues of bisphenol A (BPA) and diglycidyl ester derivatives (BDGEs) of BPA and BPF is limited. Such information is, however, important as the current debate on BPA and the lowered BPA migration limit in Europe may provide an incentive for application of structural analogues. A new sensitive multi-analyte LC-ESI-MS/MS method was developed to measure 17 bisphenols (BPs) and 6 BDGEs in food, beverages and drinkware. Yeast based bioassays were used to determine the in vitro (anti)estrogenic and (anti)androgenic properties of these and 7 additional BPs and BDGEs. Drinkware of polycarbonate and other materials were analysed for BPs and BDGEs. Only BPA and BPS and both at trace levels were found in a few containers. A limited number of (canned) foods and beverages were also analysed. BPA was the most frequently detected BP (ranged from 0.03 ng mL−1 in a beverage sample to 68 ng g−1 in food). Other BPs detected were BPS, 2,2-BPF and 4,4-BPF. In addition BADGE, BADGE.HCl, BADGE.H2O and BADGE.2H2O were detected from 0.08 ng mL−1 in a beverage sample to 3.3 ng g−1 in food. In vitro testing showed that most BPs exhibited an equal or higher estrogenic potency than BPA and most of them also showed a higher anti-androgenic potency, i.e. BPB, BPCl, BPC, BPE, 4,4-BPF, BPP, BPAF, and BPTMC. Some BPs and BDGEs were not estrogenic, but showed an anti-estrogenic effect and were anti-androgenic too. BPS was only weakly estrogenic and BADGE.2H2O and BFDGE.2H2O showed no in vitro activity. The present data show that in addition to BPA, other BPs and BDGEs can be present in food and drinks, some displaying in vitro endocrine activities.

Over 27 million individuals are affected every year worldwide with central nervous system (CNS) injuries. These injuries include but are not limited to traumatic brain injury (TBI) and spinal cord injury (SCI). CNS injuries remain a significant public health concern which demands reliable tools for rapid, on-sight, on-field, and point-of-care diagnostic (POC) solutions. To address these challenges, we developed a low-cost, open-source, hand-held, portable, and POC detection technology, termed as MicroDrop (μDrop), which can simultaneously detect up to eight target biomolecules and display results in both analog and digital formats. The data acquired is stored wirelessly in a cloud server for further investigation and statistical analysis. Multiplexing capability of μDrop and immuno-biosensors detects and quantifies Cleaved-Tau Protein (C-Tau) and Neuron-Filament (NFL) proteins in the blood of TBI patients. Immuno-biosensors rapidly sense the two target proteins in less than 30 min, with μDrop and a conventional potentiostat. C-Tau and NFL were selectively detected with μDrop within the dynamic range of 10 pg/mL - 100 ng/mL and the sensitivity range of 47 μA/pg mm2 - 65 μA/pg mm2. Comparing the biosensing performance with enzyme-linked immunosorbent assays (ELISA) shows that the immuno-biosensors combined with μDrop could successfully differentiate between clinical controls and injured patients.

Problem Quantitative measurement of proteins in bodily fluids or cellular preparations is critical for the evaluation of biomarkers or the study of complex cellular processes. While immunoassays are the most common quantitative approach used so far, they are not practical for the evaluation of multiple proteins. Microfluidic technology allows a fine spatial control in immobilizing proteins and biomolecules inside microchannels, eliminating cross-reactivity between competing analytes, and allowing rapid and sensitive detection of targeted antigens for multiple applications. We report the characterization and validation of the Simple Plex™ platform for the detection and quantification of cytokines and chemokines from human and mouse samples. Method Cytokine and chemokine expression levels were determined using Simple Plex cartridges from ProteinSimple. Serum samples were obtained from the Yale Biorepository. Results Our data demonstrate an excellent correlation between the results obtained with Simple Plex and conventional immunoassays such as ELISA and Luminex. Conclusion We describe the characterization and validation of Simple Plex, a novel multi-analyte, automated microfluidic platform that allows the evaluation of cytokines and chemokines from human and mice biological samples. Simple Plex showed significant advantages over traditional approaches in terms of low sample volume requirements, sensitivity and dynamic range, coefficient of variation, and reproducibility.

A supramolecular-gel-based twenty-two-member sensor array has been created by introducing well-designed multi-competitive binding interactions into a supramolecular gel., Sensor arrays are a powerful tool for multianalyte sensing and the development of an efficient sensor array has become one of the most intriguing problems. However, sensor arrays often employ lots of receptors which need large amounts of work to synthesise. This study describes an efficient method for the fabrication of a simple sensor array based on the competitive binding in supramolecular gels. By rationally introducing various well-designed competitive binding interactions into the supramolecular gel, which is self-assembled from a naphthylhydrazone-based organogelator, a supramolecular gel-based twenty-two-member sensor array has been created. Interestingly, the sensor array has been shown to accurately identify fourteen kinds of important ions (F–, Cl–, I–, CN–, HSO4–, SCN–, S2–, OH–, Al3+, Fe3+, Zn2+, Hg2+, Pb2+ and H+) in water. It's important to note that this sensor array needs only one synthesized receptor. Moreover, using this method, we also obtained a series of ion response fluorescent supramolecular materials, which could act as security display materials. Therefore, it's a novel and facile way for the design of a simple sensor array as well as ion response fluorescent supramolecular materials.

A rationally designed simple benzothiazole based Schiff base probe (L) exhibits distinct selective “turn-on” emission responses in the presence of Zn2+ and Cd2+ ions. Emission wavelengths over 600 nm were achieved with both the metal ions, which makes the system more viable for the study in biological complex medium. Further “turn-off” fluorometric response for the inorganic phosphates was achieved with both the L–Zn2+ and L–Cd2+ ensembles. The entire sensing process is perceptible to the naked eye and is viable in mixed buffered medium at physiological pH.