Analytical Performance Research Articles

Ellagic acid-imbedded MoO3 nanowires architecture: External mediator-less electrochemical immunoprobing of inflammatory bowel disease marker.

Ellagic acid-imbedded MoO3 nanowires architecture: External mediator-less electrochemical immunoprobing of inflammatory bowel disease marker.

An electrochemiluminescence biosensor based on metal porphyrin luminophore and covalent organic framework for the sensitive detection of ctDNA in non-small cell lung cancer.

An electrochemiluminescence biosensor based on metal porphyrin luminophore and covalent organic framework for the sensitive detection of ctDNA in non-small cell lung cancer.

Performance Evaluation of High-performance Liquid Chromatography Instrument in Determining the Serum Concentration of Linezolid

LM1010, a high-performance liquid chromatography system for therapeutic drug monitoring (TDM) of various agents in clinical practice, is currently approved in Japan. Unlike conventional systems, LM1010 can rapidly measure clinical samples, and data analysis is based on the absolute calibration curve method and fully automated. However, the analytical performance of the LM1010 for the measurement of serum concentrations of linezolid (LZD) has not yet been evaluated. In this study, we aimed to evaluate the analytical performance of LM1010 and confirm the long-term stability of LZD at -30°C. One hundred forty-eight serum samples were collected from 25 patients (17 men and 8 women) who received LZD. Serum concentrations of LZD were measured using LM1010 and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Three LM1010 instruments were used to confirm the differences in the measured values. A Passing-Bablok regression analysis demonstrated a strong correlation between LM1010 and LC-MS/MS (r=0.991), and comparable results were observed among the three LM1010 instruments (r=0.982-0.998). Bland-Altman analyses revealed that the average difference between LM1010 and LC-MS/MS methods was 1.7%, and similar results were observed among the three LM1010 instruments. The long-term stability of serum LZD in samples stored at -30°C for 48 weeks was also confirmed. These results suggest that LM1010 can be used for TDM of LZD in clinical practice.

Validation for soluble C5b-9 detection and comparative analysis of three quantification methods.

Validation for soluble C5b-9 detection and comparative analysis of three quantification methods.

Harmonisation of the diagnostic performances of serological ELISA tests for C. burnetii in ruminants in the absence of a gold standard: Optimal cut-offs and performances reassessment.

Harmonisation of the diagnostic performances of serological ELISA tests for C. burnetii in ruminants in the absence of a gold standard: Optimal cut-offs and performances reassessment.

Quantification of trimethylamine-N-oxide (TMAO) and its main related trimethylammonium-containing compounds in human plasma by LC-MS/MS.

Quantification of trimethylamine-N-oxide (TMAO) and its main related trimethylammonium-containing compounds in human plasma by LC-MS/MS.

Evaluating the performance of the Xpert HPV assay in detecting HPV positive cases in Morocco.

Evaluating the performance of the Xpert HPV assay in detecting HPV positive cases in Morocco.

Assessment of accuracy, clinical validity, and analytical linearity in point-of-care glucose monitoring devices for diabetes mellitus: A systematic review and meta-analysis.

Assessment of accuracy, clinical validity, and analytical linearity in point-of-care glucose monitoring devices for diabetes mellitus: A systematic review and meta-analysis.

Performance verification of the new UF-1500 urine particle analyser: a new opportunity for small and medium laboratories

Performance verification of the new UF-1500 urine particle analyser: a new opportunity for small and medium laboratories

Simultaneous detection and differentiation of Mycobacterium tuberculosis and nontuberculous mycobacteria in smear-negative sputum by a multiplex PCR assay: a clinical feasibility study.

Accurate and rapid differentiation of Mycobacterium tuberculosis (M. tuberculosis) and nontuberculous mycobacteria (NTM) remains challenging, especially in smear-negative samples. Routine diagnostic methods often lack specificity and rapidity, highlighting the urgency of developing applicative molecular diagnostics to guide clinical management and improve patient outcomes. We developed and validated a multiplex PCR assay employing TaqMan probes targeting the IS6110 and rpoB genes to simultaneously detect M. tuberculosis and 23 NTM species in a single reaction, while avoiding cross-reactivity. Analytical performance was assessed using reference strains, and clinical feasibility was evaluated in a prospective, single-center pilot study involving 96 smear-negative presumptive tuberculosis patients. The assay's diagnostic performance was compared to mycobacterial culture, DNA sequencing, and the Xpert MTB/RIF assay. The multiplex PCR assay demonstrated a wide linear dynamic range (108-103 copies/mL), low limit of detection (103 copies/mL), high precision (intra-assay CV 0.05-1.18%, inter-assay CV 0.08-2.57%), and complete specificity for both M. tuberculosis and NTM. In the clinical feasibility study, using a combination of clinical diagnosis and mycobacterial culture as reference standards, it achieved sensitivities of 73.33% (M. tuberculosis) and 100% (NTM), and specificities of 100% (M. tuberculosis) and 94.33% (NTM). Notably, it reliably identified M. tuberculosis/NTM co-infections. The Multiplex PCR assay fills a critical gap in the rapid, accurate diagnosis of M. tuberculosis and NTM in challenging clinical specimens. With a cost of $5 per test and a turnaround time of 3 h, our assay has the potential to improve patient care and optimize mycobacterial infection treatment strategies in resource-limited settings.IMPORTANCERapid and accurate differentiation between Mycobacterium tuberculosis (M. tuberculosis) and nontuberculous mycobacteria (NTM) is essential for ensuring timely and appropriate treatment, especially in high tuberculosis (TB) burden regions. Conventional diagnostic methods, such as smear microscopy and culture, often lack the sensitivity or speed needed for reliable results in smear-negative cases, risking misdiagnosis and delayed care. In this study, we developed a novel multiplex real-time PCR assay capable of simultaneously detecting M. tuberculosis and up to 23 clinically relevant NTM species with high specificity and sensitivity. By targeting distinct genetic markers for M. tuberculosis and NTM, our assay provides a cost-effective, 3-h diagnostic solution that enhances diagnostic accuracy in challenging samples. This innovation addresses a critical gap in mycobacterial diagnostics, supporting improved patient outcomes and aligning with global health priorities for the control and elimination of TB.

Surface Relief Gratings of Slide-Ring Hydrogels for Label-Free Biosensing

The creation of surface relief gratings using hydrogels for label-free biomolecule detection represents a significant advance in the development of versatile, cutting-edge biosensors. Central to this innovation is the formulation of materials with enhanced mechanical properties, especially for applications in soft, wearable technologies. In this work, we have developed novel biofunctional hydrogels that incorporate slide-ring supramolecular structures into their network, enabling the production of surface relief gratings with superior mechanical characteristics for biomolecule detection without the need for labels. These hydrogels, functionalized with bovine serum albumin and goat anti-rabbit antibodies, demonstrated excellent selectivity and sensitivity toward anti-bovine serum albumin and rabbit IgGs in blood serum, evaluated using a label-free format. Remarkably, the new materials matched the analytical performance of conventional hydrogels based on static networks while offering dramatically improved toughness and elasticity, with a compressive modulus comparable to human skin. This demonstrates the potential of slide-ring hydrogels for fabricating robust, label-free biosensing platforms. Furthermore, the flexibility of this system allows for the incorporation of various recognition elements tailored to specific applications.

Carbon Black Single Piece Electrodes for Nitrate Ion Sensing.

This work presents an idea for a new reliable potentiometric sensor for nitrate ion determination. The paper provides the optimized procedure for the preparation and maintenance of single-piece nitrate-selective electrodes with carbon black nanoparticles. The optimal carbon black amount was selected based on the electrical properties of the designed sensors. The 5% addition of carbon nanomaterial to the polymeric membrane ensured the highest electrical capacitance (of 610 µF) and the lowest resistance (of 421 kΩ); therefore, this amount was further applied to design single-piece sensors. The influence of carbon black incorporation into the membrane on the analytical performance of the nitrate-selective electrodes was investigated, focusing on parameters such as sensitivity, selectivity, detection limit, and potential stability. Carbon black-modified nitrate-selective sensors exhibit a near-Nernstian response in a wide range of nitrate ion concentrations (with a detection limit of 7 × 10-7). Remarkable potential stability, ensured by the hydrophobic properties of the modified membrane, was evaluated during the water-layer test and the calculated potential drift equaled 0.052 mV/h.

Analytical performance evaluation of intelligent quality management of blood gas analyzer

Analytical performance evaluation of intelligent quality management of blood gas analyzer

Impact of analytical bias on machine learning models for sepsis prediction using laboratory data

Abstract Objectives Machine learning (ML) models, using laboratory data, support early sepsis prediction. However, analytical bias in laboratory measurements can compromise their performance and validity in real-world settings. We aimed to evaluate how analytically acceptable bias may affect the validity and generalizability of ML models trained on laboratory data. Methods A support vector machine model (SVM) for sepsis prediction was developed using complete blood count and erythrocyte sedimentation rate data from outpatients (CS, n=104) and patients from acute inflammatory status wards (SS, n=107). Twenty-six combinations were derived by white blood cells (WBC), platelets (PLT), and erythrocyte sedimentation rate (ESR) biases from analytical performance specifications (APS). The diagnostic performances of the 26 conditions tested were compared to the original dataset. Results SVM performance of the original dataset was AUC 90.6 % [95 %CI: 80.6–98.7 %]. Minimum, desirable and optimum acceptable biases for WBC were 7.7 , 5.1 and 2.6 %, respectively, for PLT were 6.7 , 4.5 and 2.2 %, respectively and for ESR were 31.6 , 21.1 and 10.5 %, respectively. Across all conditions, AUC varied from 89.8 % [95 %CI: 79.0–97.7 %] (for PLT bias −6.7 %), to 89.5 % [95 %CI: 79.1–98.0 %] (for ESR Bias +31.6 %) to 90.4 % [95 %CI: 79.3–98.4 %] (for WBC Bias −5.1 %). Using a combination of biases, the lowest AUC was 87.8 % [95 %CI: 75.9–96.6 %]. No statistically significant differences were observed for AUC (p>0.05). Conclusions Bias can influence model performance depending on the parameters and their combinations. Developing new validation strategies to assess the impact of analytical bias on laboratory data in ML models could improve their reliability.

Detection of HPV-16 by a Simple and Cost-Effective DNA Probe: Polyadenine-Polythymine-Decorated Gold Nanoparticles (PolyA-PolyT@AuNPs).

HPV-16 identification is crucial for point-of-care molecular diagnosis of cervical cancer. However, the diagnostic methods currently in use are unable to combine both high analytical performance and cost-efficient medical diagnosis. To circumvent this, we have developed a novel nanobiosensor for diagnosis of the HPV-16 L1 gene sequence through colorimetric methods. Using a unique conjugation technique of polyvalent DNA to gold nanoparticles (AuNPs), quickly synthesizing AuNPs synthesis in situ at the particular probe-polyadenine-polythymine (A15-T10) strands was developed. Transmission electron microscopy (TEM), dynamic light scattering (DLS), gel electrophoresis, UV-Vis spectroscopy, and visual detection demonstrate that the Poly(A)15-(T)10 strand can create separate anisotropic AuNPs so that a thick layer of DNA is functionalized on each AuNP, therefore generating polyvalent (p)DNA-AuNPs. Moreover, the hybridization test, UV-Vis spectroscopy, TEM, visual detection, and DLS results further confirmed the innovative sensing applicability, showing more excellent attractiveness of pDNA-AuNPs conjugation in diagnostics in biomedicine and particular sequence detection, such as double-stranded DNA (dsDNA) by employing probe-polyA-polyT extra-strands that are in harmony with the intended sequence. This sensor demonstrated good performance levels with a sensitivity of up to 1.9nM for pUCm-T. Additionally, the sensor showed intense discrimination against actual clinically collected HPV-16 samples, consistent stability, and good repeatability.

Simultaneous Determination of Glibenclamide, Metoprolol Tartrate, and Phenol Red Using HPLC-PDA: Application in Rat Intestinal Permeability Studies and Its Greenness Assessment Using NEMI, Analytical Eco-Scale, GAPI, MoGAPI, AGREE, AGREEprep, RAPI, BAGI, and CACI.

ABSTRACTThis study presents the development and validation of an environmentally friendly HPLC‐PDA method for the simultaneous determination of glibenclamide (GLB), metoprolol tartrate (MET), and phenol red (PR). The method was optimized to ensure high trueness, precision, and robustness, adhering to ICH guidelines. The pKa of GLB was determined using reverse‐phase HPLC under varying pH conditions, providing valuable insights into its physicochemical properties and enhancing its pharmaceutical formulation potential. Intestinal permeability studies of GLB, conducted via the in situ Single Pass Intestinal Perfusion (SPIP) technique, validated the method's applicability in biological systems. In addition to analytical performance, the environmental sustainability of the method was assessed using green metrics, including the Analytical Eco‐Scale, GAPI, MoGAPI, AGREE, AGREEprep RAPI, BAGI, and CACI. The method achieved high scores, reflecting its alignment with the principles of green analytical chemistry and its minimal ecological impact. This dual focus on analytical rigor and environmental responsibility emphasizes the method's potential for broader applications in pharmaceutical and biomedical research. The findings of this study contribute to the ongoing efforts in developing sustainable analytical methodologies. Future research could explore its applicability to other pharmaceutical compounds and expand its use in complex matrices, further promoting environmentally conscious practices in analytical chemistry.

Sustainable uric acid sensor based on a lab-fabricated electrode modified with rice straw-derived carbon materials

A novel and facile electrochemical sensor for the quantification of uric acid has been fabricated through the strategic modification of a screen-printed carbon electrode (SPCE) using mesoporous carbon-zinc oxide (MC-ZnO) synthesized from rice straw waste. The MC-ZnO materials, generated via a controlled pyrolysis process, exhibit homogeneous dispersion and a substantial electroactive surface area of 0.1286 cm2. The electrochemical oxidation of uric acid exhibits a distinct peak at 0.18 V in differential pulse voltammetry (DPV), indicative of efficient charge transfer kinetics. A linear range spanning 20 to 225 µM was obtained with a limit of detection (LOD) of 3.76 µM, signifying exceptional analytical sensitivity. Furthermore, the sensor demonstrates robust selectivity toward uric acid in the presence of typical interferents, underscoring its applicability for precise uric acid determination in complex biological matrices. The sensor’s analytical performance was validated by quantifying uric acid in spiked urine samples, yielding recovery rates between 97.9% and 114.8% and relative standard deviations (RSD) below 4.92%, affirming its accuracy and precision. This platform heralds a promising avenue for clinical diagnostics, leveraging sustainable materials for uric acid detection.

CRISPR-Cas12a/Aurora Deoxyribozyme Cascade: A Label-Free Ultrasensitive Platform for Rapid Salmonella Detection.

The rapid and ultrasensitive detection of Salmonella holds strategic significance for food safety surveillance and public health protection systems. This study innovatively developed a label-free biosensing platform based on the synergistic integration of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas12a and the fluorescent deoxyribozyme Aurora for the efficient detection of foodborne Salmonella. The detection mechanism operates through a molecular cascade reaction: target-activated Cas12a protein specifically degrades Aurora deoxyribozyme via its trans-cleavage activity, thereby abolishing the enzyme's catalytic capability to convert 4-methylumbelliferyl phosphate (4-MUP) into the highly fluorescent product 4-methylumbelliferone (4-MU). This cascade ultimately enables quantitative target analysis through fluorescence signal attenuation. Following systematic optimization of critical reaction parameters, the biosensing system demonstrated exceptional analytical performance: a detection limit of 1.29 CFU/mL with excellent linearity (R2 = 0.992) spanning six orders of magnitude (1.65 × 101-106 CFU/mL), along with high specificity against multiple interfering bacterial strains. Spike-and-recovery tests in complex food matrices (milk, chicken, and lettuce) yielded recoveries of 90.91-99.40% (RSD = 3.55-4.72%), confirming robust practical applicability. Notably, the platform design allows flexible detection of other pathogens through simple replacement of CRISPR guide sequences.

Rapid clinical deployment of UBA1 testing in patients with VEXAS syndrome.

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is a recently described autoinflammatory syndrome caused by pathogenic variants in UBA1. However, there is a dearth of widely available UBA1 testing aside from large, expensive sequencing studies. Thus, we sought to rapidly develop, validate, and clinically deploy a cost-effective assay for detecting the most common UBA1 variants. We developed, validated, and implemented a single base extension mass spectrometry assay for detecting pathogenic UBA1 variants at the c.121, c.122, and c.118-1 positions in patients with suspected VEXAS syndrome. Assay performance characteristics were assessed using peripheral blood and bone marrow samples from patients with (n = 8) and without (n = 36) VEXAS. The assay demonstrated a lower limit of detection (LOD) of 10% variant allele fraction for each mutation. The analytical accuracy, sensitivity, and specificity were each demonstrated to be 100% at the LOD, with excellent intra- and interrun reproducibility. Based on literature review of reported UBA1 variants associated with VEXAS, to date, this assay detects the most prevalent variants, with a clinical sensitivity of 97% or more. A cost-effective, mass spectrometry-based assay with high analytical and clinical performance can feasibly be implemented in hospital laboratories for diagnosis of VEXAS syndrome.

Challenges in Hb A1c Point-of-Care Testing: Only 5 of 19 Hb A1c Point-of-Care Devices Meet IFCC and NGSP Certification Criteria on Independent Evaluation.

Access to Hb A1c testing in low- and middle-income countries (LMICs) can be limited, especially in rural areas. This has led to an increased interest in the potential role of point-of-care testing (POCT) for Hb A1c. The analytical performance of many of these devices is poorly understood but accurate and precise measurement is essential for effective diabetes management. Verification of the manufacturers' claims, for accuracy, imprecision, and interference from hemoglobin variants, was performed using protocols based on established guidance using Clinical and Laboratory Standards Institute (CLSI) protocols (EP-15-A3 and EP-9-A3), international quality targets and 4 certified International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and National Glycohemoglobin Standardization Program (NGSP) Secondary Reference Measurement Procedures (SRMP). Each of the 19 POC devices were assessed for performance against both IFCC and NGSP certification criteria. Out of 19 Hb A1c POC devices, only 5 (26%) met international quality criteria (IFCC and NGSP with at least one SRMP), 5 (26%) only met IFCC criteria, and 9 (47%) did not meet either IFCC or NGSP criteria, despite most of these devices having an IFCC and/or NGSP certificate at the time of the study. Three devices showed clear interference from Hb variants. This study shows the importance of independent evaluations for assessing the performance of Hb A1c POC devices. The analytical performance of the devices was very poor overall, with 74% not meeting both IFCC and NGSP criteria. These evaluations were performed under ideal conditions; performance may worsen further when used in a clinical setting.