Study on the Impact of Pole Spacing on Magnetic Flux Leakage Detection under Oversaturated Magnetization.

Magnetic flux leakage (MFL) inspection employs leakage magnetic fields to effectively detect and locate pipeline defects. The spacing between magnetic poles significantly affects the leakage magnetic field strength. While most detectors typically opt for moderate pole spacing for routine detection, this study investigates the propagation characteristics of MFL signals at small pole spacings (under specimen oversaturated magnetization) and their impact on MFL detection. Through finite element simulation and experiments, it reveals a new signal phenomenon in the radial MFL signal By at small pole spacings, the double peak-valley (DPV) phenomenon, characterized by outer and inner peaks and valleys. Theoretical analysis based on the simulation results elucidates the mechanisms for this DPV phenomenon. Based on this, the impact of defect size, pipe wall thickness, and magnetic pole and rigid brush height on MFL signals under small magnetic pole spacings is examined. It is demonstrated that, under a smaller magnetic pole spacing, a potent background magnetic field manifests in the air above the defect. This DPV phenomenon is generated by the magnetic diffusion and compression interactions between the background and defect leakage magnetic fields. Notably, the intensity of the background magnetic field can be mitigated by reducing the height of the rigid brush. In contrast, the pipe wall thickness and magnetic pole height exhibit a negligible influence on the DPV phenomenon. The emergence of the DPV precipitates a reduction in the peak-to-valley difference within the MFL signal, constricting the depth range of detectable defects. However, the presence of DPV increases the identification of defects with smaller opening sizes. These findings reveal the characterization of the MFL signal under small pole spacing, offering a preliminary study on identifying specific defects using unconventional signals. This study provides valuable guidance for MFL detection.

Synthesis of Copper Molybdate and Its Electrochemical Sensing of Paracetamol.

Background In recent years, significant advancements have been made in various scientific sectors, particularly in healthcare and pharmaceutical research. This progress has been driven by the development of enhanced sensing materials and methodologies. Electrochemical sensing has become an important tool in detecting and analyzing drug molecules due to its high sensitivity, specificity, and rapid response times. Among various drugs, paracetamol, also known as acetaminophen, is widely used for its analgesic and antipyretic properties. Accurate detection of paracetamol is crucial due to its widespread use and potential for overdose, which can lead to severe liver damage. Copper molybdate (CuMoO4) is a transition metal oxide that has garnered attention for its excellent electrical conductivity and electrochemical stability. These properties make it a promising candidate for use in electrochemical sensors. The ability of CuMoO4 to act as a sensor material is enhanced by its unique structural and morphological characteristics, which can be tailored during synthesis. Aim This study aimed to synthesize CuMoO4 and investigate its electrochemical sensing capability for the detection of drug molecules, specifically paracetamol. Materials and method CuMoO4 was synthesized using a precipitation method that did not involve any surfactants. This approach was chosen to simplify the synthesis process and avoid potential contamination from surfactants. The morphology of the synthesized CuMoO4 nanoparticles was investigated using a field emission scanning electron microscope (FE-SEM). Energy-dispersive X-ray spectroscopy (EDX) confirmed the purity of the CuMoO4 nanomaterial. Structural analysis was performed using X-ray diffraction (XRD). To evaluate the electrochemical sensing capability of CuMoO4 for paracetamol, Differential pulse voltammetry (DPV) was employed. DPV is a sensitive electrochemical technique that can detect changes in current response corresponding to the presence of analytes. Results The synthesized CuMoO4 exhibited a rock-like structure, as revealed by FE-SEM imaging. This morphology is advantageous for electrochemical applications due to the increased surface area available for interaction with analytes. EDX confirmed the purity of the CuMoO4 nanomaterial, showing no significant impurities. XRD analysis indicated that the CuMoO4 nanoparticles were crystalline in nature, which is beneficial for consistent and reproducible electrochemical behavior. The DPV analysis demonstrated that the CuMoO4 sensor exhibited a linear increase in current response with increasing concentrations of paracetamol. This linear relationship indicates that CuMoO4 is capable of detecting paracetamol effectively, with a strong and quantifiable signal response. Conclusion The CuMoO4 nanomaterial was successfully synthesized using a simple precipitation method and was characterized by its rock-like morphology and crystalline structure. Electrochemical testing using DPV showed that CuMoO4 has excellent sensing capabilities for detecting paracetamol, with a clear and linear current response. These findings suggest that CuMoO4 is a promising electrochemical sensing material for drug detection, potentially offering a reliable and efficient method for monitoring paracetamol and possibly other pharmaceuticals in various settings.

Rapid detection of SARS-CoV-2 spike protein using a magnetic-assisted electrochemical biosensor based on functionalized CoFe2O4 magnetic nanomaterials.

The outbreak of novel coronavirus pneumonia (COVID-19) in 2019 has garnered widespread attention. The virus exhibits high contagiousness, and in certain cases, it can lead to recurrent infections. Therefore, it is imperative to develop portable, sensitive, and accurate sensors to promptly detect infected individuals, control the virus's transmission, and determine suitable treatment strategies. In this study, we proposed a magnetically-assisted method employing CFO@CS-Au MNP as the substrate material, which was functionalized with human angiotensin-converting enzyme (ACE2) for efficient capture of SARS-CoV-2 spike protein in solution. Subsequently, the captured protein was sensitively detected through differential pulse voltammetry (DPV) electrical analysis. The linear detection range of the labeled GCE/MNP/GA/ACE2/BSA electrochemical sensor is from 1 pg/mL to 10 µg/mL, with a minimum detection limit of 0.15 pg/mL. Furthermore, the fabricated GCE/MNP/GA/ACE2/BSA sensor achieved satisfactory recoveries of SARS-CoV-2 spike protein in saliva and nasal swab samples within 10 min. These results indicate that this magnetically-assisted biosensor has established a solid foundation for the swift on-site detection of COVID-19.

Triangle-Shaped Cerium Tungstate Nanoparticles Used to Modify Carbon Paste Electrode for Sensitive Hydroquinone Detection in Water Samples.

In this study, we propose an eco-friendly method for synthesizing cerium tungstate nanoparticles using hydrothermal techniques. We used scanning, transmission electron microscopy, and X-ray diffraction to analyze the morphology of the synthesized nanoparticles. The results showed that the synthesized nanoparticles were uniform and highly crystalline, with a particle size of about 50 nm. The electrocatalytic properties of the nanoparticles were then investigated using cyclic voltammetry and electrochemical impedance spectroscopy. We further used the synthesized nanoparticles to develop an electrochemical sensor based on a carbon paste electrode that can detect hydroquinone. By optimizing the differential pulse voltammetric method, a wide linearity range of 0.4 to 45 µM and a low detection limit of 0.06 µM were obtained. The developed sensor also expressed excellent repeatability (RSD up to 3.8%) and reproducibility (RSD below 5%). Interferences had an insignificant impact on the determination of analytes, making it possible to use this method for monitoring hydroquinone concentrations in tap water. This study introduces a new approach to the chemistry of materials and the environment and demonstrates that a careful selection of components can lead to new horizons in analytical chemistry.

Interaction mechanism of a pesticide, Azoxystrobin with bovine serum albumin: Assessments through fluorescence, UV-Vis absorption, electrochemical and molecular docking simulation techniques.

The current study's objective was to investigate how an antifungal pesticide Azoxystrobin (AZO) interacts with bovine serum albumin (BSA) under conditions that simulate a physiological medium (pH 7.4). This investigation was carried out using various experimental (UV-Vis absorption, steady-state fluorescence and 3-D fluorescence spectroscopies, and electrochemical) and theoretical (molecular docking and molecular dynamics simulations) methods. The fluorescence quenching data demonstrated that AZO caused fluorescence quenching in BSA, and this quenching process was attributed to the static quenching mechanism. By examining the fluorescence quenching of BSA at three different temperatures, it was determined that the binding constants for the AZO-BSA complexes were approximately 104 M-1 in magnitude, while the same magnitude of the binding constant was found by the electrochemical method. This indicates that the interaction between AZO and BSA was of moderate strength. This was further validated by the changes observed in the UV-Vis spectrum of BSA following the addition of AZO. The thermodynamic information, including ΔH and ΔS, revealed that the interaction forces primarily involved van der Waals forces as well as hydrogen bonds. The negative Gibbs free energy indicated that the reaction is spontaneous. In the theoretical investigation, the comparison highlights a remarkable consistency in how AZO interacts with the BSA active site over various time points. Hydrogen bonding and hydrophobic interactions consistently play a role in ensuring the stable and specific binding of the ligand. Moreover, the 3-D fluorescence spectral findings revealed alterations in the surrounding microenvironment of protein fluorophores when AZO binds. Upon analyzing the electrochemical data, it was observed that there was a consistent decrease in the peak currents of AZO when BSA was added to solutions containing AZO. The primary cause of this decrease in the peak currents was the reduction in the equilibrium concentration of AZO due to the addition of BSA. Furthermore, the formation of a non-electroactive complex between BSA and AZO, which impedes electron transport between AZO and the working electrode, accounts for these decreases. As a result, it can be said that the understanding of how AZO binds to BSA offers valuable insights that can be applied in the food, human health, and environment sectors.

Family structures and parents' occupational models: its impact on children's diabetes.

AIMS: This study examines how family-related factors influence the management of children and adolescents with type 1 diabetes (T1DM). We investigate the relationship between family patterns, parental work schedules and metabolic control. MATERIALS AND METHODS: We analysed data from a nationwide diabetes survey (DPV) focusing on HbA1c, severe hypoglycaemia, diabetic ketoacidosis, hospital admissions and inpatient treatment duration. We used linear regression and negative binomial regression models. Our study includes 15,340 children under the age of 18 with data on family structure and parental division of labour. RESULTS: Children from two-parent households have better HbA1c outcomes than children from single-parent, blended or no-parent households (p < .0001). Higher HbA1C levels are associated with children living with an unemployed father, as opposed to those with full-time working parents or with a full-time working father and a part-time working mother (p < .001). CONCLUSIONS: These findings emphasise the importance of carefully considering family structure and working time models in the management of paediatric T1DM. Our results highlight risk factors within the family environment and emphasise the need for family-focused counselling of high-risk patients or severe cases in clinical practice.

Continuous glucose monitoring in older adults with diabetes: Data from the diabetes prospective follow-up (DPV) registry.

AIMS: To analyse predictors for continuous glucose monitoring (CGM) use in people with diabetes aged ≥60 years using insulin therapy and to assess the rates of CGM use during recent years (2019-2021). RESEARCH DESIGN AND METHODS: Prospective study including 6849 individuals with diabetes and insulin therapy (type 2 diabetes: n = 5320; type 1 diabetes: n = 1529) aged ≥60 years. Data from 129 treatment centres were retrieved from the Diabetes Prospective Follow-up Registry (DPV) in March 2023. RESULTS: Sensor use in individuals aged ≥60 years has increased in type 1 (2019: 28%, 2020: 39%, 2021: 45%) and type 2 diabetes (2019: 10%, 2020: 16%, 2021: 18%). Predictors for sensor use in older individuals with type 1 diabetes are younger age and CSII use (p < 0.001). Predictors in older individuals with type 2 diabetes are younger age, longer diabetes duration, higher BMI and CSII use (p < 0.001). CONCLUSIONS: CGM has become more common in older adults with diabetes and will presumably increase further. Age is a predictor for sensor use in older adults with diabetes. Age-related physical barriers and insufficient usability of devices, lack of interest in technologies, but possibly also effects of prejudice on the grounds of age may contribute to this finding.

PFAS Electroanalysis in Low-Oxygen River Water Using Electrogenerated Dioxygen.

Per- and polyfluoroalkyl substances (PFAS), nicknamed "forever chemicals" due to the strength of their carbon-fluorine bonds, are a class of potent micropollutants that cause deleterious health effects in mammals. The current state-of-the-art detection method requires the collection and transport of water samples to a centralized facility where chromatography and mass spectrometry are performed for the separation, identification, and quantification of PFAS. However, for efficient remediation efforts to be properly informed, a more rapid in-field testing method is required. We previously demonstrated the development and use of dioxygen as the mediator molecule. The use of dioxygen is predicated on the assumption that there will be consistent ambient dioxygen levels in natural waters. This is not always the case in hypoxic groundwater and at high altitudes. To overcome this challenge and further advance the strategies that will enable in-field electroanalysis of PFAS, we demonstrate, as a proof of concept, that dioxygen can be generated in solution through the hydrolysis of water. The electrogenerated dioxygen can then be used as a mediator molecule for the indirect detection of PFOS via molecularly imprinted polymer (MIP)-based electroanalysis. We demonstrate that calibration curves can be constructed with high precision and sensitivity (LOD < 1 ppt or 1 ng/L). Our results provide a foundation for enabling in-field hypoxic PFAS electroanalysis.

MoS2/S@g-CN Composite Electrode for L-Tryptophan Sensing.

L-tryptophan (L-TRP) is an essential amino acid responsible for the establishment and maintenance of a positive nitrogen equilibrium in the nutrition of human beings. Therefore, it is vital to quantify the amount of L-tryptophan in our body. Herein, we report the MoS2/S@g-CN-modified glassy carbon electrode for the electrochemical detection of L-tryptophan (L-TRP). The MoS2/S@g-CN composite was successfully synthesized using an efficient and cost-effective hydrothermal method. The physical and chemical properties of the synthesized composite were analyzed using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray analysis (EDX). The crystallite size of the composite was calculated as 39.4 nm, with porous balls of MoS2 decorated over the S@g-CN surface. The XPS spectrum confirmed the presence of Mo, S, O, C, and N elements in the sample. The synthesized nanocomposite was further used to modify the glassy carbon (GC) electrode (MoS2/S@g-CN/GC). This MoS2/S@g-CN/GC was used for the electrochemical detection of L-TRP using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. For the purpose of comparison, the effects of the scanning rate and the concentration of L-TRP on the current response for the bare GC, S@g-CN/GC, MoS2/GC, and MoS2/S@g-CN/GC were studied in detail. The MoS2/S@g-CN-modified GC electrode exhibited a rational limit of detection (LoD) of 0.03 µM and a sensitivity of 1.74 µA/ µMcm2, with excellent stability, efficient repeatability, and high selectivity for L-TRP detection.

Electrochemical immunosensor based on titanium dioxide grafted MXene for EpCAM antigen detection.

This study proposes the fabrication of a highly sensitive electrochemical immunosensor for label-free detection of EpCAM antigen. MXenes, novel 2D materials have become popular owing to their unique electrochemical properties. Unlike conventional immunosensors, which are unable to detect the carcinoma at primary stage and also time consuming, the use of highly conducting MXene provides a label-free and highly sensitive immunosensor. Herein, we develop a unique immunosensor, which is based on the in-situ growth of 2D-TiO2 onto the novel 2D-Ti3C2Tx sheets by hydrothermal treatment. The 2D/2D TiO2/Ti3C2Tx hybrid provides a platform having a large effective surface area, and more number of electrochemically active sites to enhance the electron transfer rate through the redox probe. The designed sensing platform, BSA/anti-EpCAM/TiO2/Ti3C2Tx@ITO shows a broad linear range (1 ag/mL to 10 ng/mL) with high sensitivity (6.661 µA ag-1 mL cm-2), and low detection limit (0.7 ag/mL) for EpCAM antigen detection under optimized conditions. The proposed immunosensor possesses good reproducibility, long-term stability, and outstanding selectivity and specificity. Moreover, the clinical applicability of the novel immunosensor is tested in spiked human serum showing good recovery.

Neuropathy in paediatric type 1 diabetes mellitus - clinical characterization and analysis of risk factors in the diabetes prospective follow-up registry DPV (Diabetes-Patienten-Verlaufsdokumentation)-registry.

OBJECTIVES: Data on the prevalence, clinical features and risk factors associated with paediatric diabetic neuropathy (DN) are scarce. METHODS: We retrospectively analysed data from the DPV registry, including patients under 20 years of age, treated for type 1 diabetes mellitus (T1D) between 2005 and 2021. Patients with non-diabetic neuropathy were excluded. Data came from centres in Austria, Germany, Luxembourg and Switzerland. RESULTS: 1,121 of the 84,390 patients included had been diagnosed with DN. Univariate analysis showed patients with DN to be older and predominantly female, with a longer duration of T1D, higher insulin dosages per kg and day, lower rates of insulin pump therapy, higher postprandial glucose-, higher HbA1c-and higher cholesterol levels, and higher diastolic and systolic blood pressure values. There was also a larger proportion of smokers and higher prevalence of diabetic retinopathy. Median duration of diabetes at diagnosis of DN was 8.3 years. Multivariable analysis, adjusted for demographics revealed an increased risk for DN among female patients and those who were older, underweight (BMI-SDS), smoked cigarettes or had a longer duration of T1D or higher levels of HbA1c and postprandial blood glucose. The presence of retinopathy and higher cholesterol levels were also linked to increased risk while not-using insulin pump therapy was not. CONCLUSIONS: DN can develop after just a short duration of T1D. Prevention may be achieved by a lowering of HbA1c-and postprandial glucose levels through improved glycaemic control. This warrants further investigation. The slight female predominance suggests further hormonal and genetic etiological factors.

Detection of Cd2+ based on Nano-Fe3O4/MoS2/Nafion/GCE sensor.

It is necessary to detect cadmium ions in seawater with high sensitivity because the pollution of cadmium ions seriously endangers the health and life of human beings. Nano-Fe3O4/MoS2/Nafion modified glassy carbon electrode was prepared by a drop coating method. The electrocatalytic properties of Nano-Fe3O4/MoS2/Nafion were measured by Cyclic Voltammetry (CV). Differential Pulse Voltammetry (DPV) was used to study the stripping Voltammetry response of the modified electrode to Cd2+. The optimal conditions were determined: In 0.1 mol/L HAc-NaAc solution, the solution pH was 4.2, the deposition potential was - 1.0 V, and the deposition time was 720 s, the membrane thickness was 8 µL. Under the optimum condition, the linear relation of Cd2+ concentration was found in the range of 5-300 µg/L, and the detection limit was 0.053 µg/L. The recovery of Cd2+ in seawater ranged from 99.2 to 102.9%. A composite material with simple operation, rapid response and high sensitivity was constructed for the determination of Cd2+ in seawater.

Electrochemical Detection of Different Foodborne Bacteria for Point-of-Care Applications.

Bacterial infections resulting from foodborne pathogenic bacteria cause millions of infections that greatly threaten human health and are one of the leading causes of mortality around the world. To counter this, the early, rapid, and accurate detection of bacterial infections is very important to address serious health issue concerns. We, therefore, present an electrochemical biosensor based on aptamers that selectively bind with the DNA of specific bacteria for the accurate and rapid detection of various foodborne bacteria for the selective determination of bacterial infection types. Different aptamers were synthesized and immobilized on Au electrodes for selective bindings of different types of bacterial DNA (Escherichia coli, Salmonella enterica, and Staphylococcus aureus) for the accurate detection and quantification of bacterial concentrations from 101 to 107 CFU/mL without using any labeling methods. Under optimized conditions, the sensor showed a good response to the various concentrations of bacteria, and a robust calibration curve was obtained. The sensor could detect the bacterial concentration at meager quantities and possessed an LOD of 4.2 × 101, 6.1 × 101, and 4.4 × 101 CFU/mL for S. Typhimurium, E. Coli, and S. aureus, respectively, with a linear range from 100 to 104 CFU/mL for the total bacteria probe and 100 to 103 CFU/mL for individual probes, respectively. The proposed biosensor is simple and rapid and has shown a good response to bacterial DNA detections and thus can be applied in clinical applications and food safety monitoring.

A Novel Electrochemical Differentiation between Exosomal-RNA of Breast Cancer MCF7 and MCF7/ADR-Resistant Cells.

Cancer is considered one of the most burdensome diseases affecting lives and, hence, the economy. Breast cancer is one of the most common types of cancer. Patients with breast cancer are divided into two groups: one group responds to the chemotherapy, and the other group resists the chemotherapy. Unfortunately, the group which resists the chemotherapy is still suffering the pain associated with the severe side effects of the chemotherapy. Therefore, there is a critical need for a method to differentiate between both groups before the administration of the chemotherapy. Exosomes, the recently discovered nano-vesicles, are often used as cancer diagnostic biomarkers as their unique composition allows them to represent their parental cells, which makes them promising indicators for tumor prognosis. Exosomes contain proteins, lipids, and RNA that exist in most body fluids and are expelled by multiple cell types, including cancer cells. Furthermore, exosomal RNA has been significantly used as a promising biomarker for tumor prognosis. Herein, we have developed an electrochemical system that could successfully differentiate between MCF7 and MCF7/ADR depending on the exosomal RNA. The high sensitivity of the proposed electrochemical assay opens the door for further investigation that will address the other type of cancer cells.

Establishment and application of a PCR assay for the identification of virulent and attenuated duck plague virus DNA in cotton swabs.

Duck plague is an acute, febrile, and septic infectious disease caused by duck plague virus (DPV), which causes serious harm to the duck industry in China. Ducks latently infected with DPV display a clinically healthy state, which is one of the epidemiological characteristics of duck plague. In the present study, to rapidly distinguish vaccine-immunized ducks from wild virus-infected ducks during production, a PCR assay based on the newly identified LORF5 fragment was developed to effectively and accurately identify viral DNA in cotton swab samples and was used to assess artificial infection models and clinical samples. The results showed that the established PCR method had good specificity and that only the virulent and attenuated DNA of duck plague virus was specifically amplified, as the results for the detection of common duck pathogens (duck hepatitis B virus, duck Tembusu virus, duck hepatitis A virus type 1, novel duck reovirus, Riemerella anatipestifer, Pasteurella multocida, and Salmonella) were negative. The amplified fragments of virulent and attenuated strains were 2,454 bp and 525 bp, and their minimum detection amounts were 0.46 pg and 46 pg, respectively. The detection rate of the virulent and attenuated DPV strains in duck oral and cloacal swabs was lower than that of the gold standard PCR method (GB-PCR, which is unable to distinguish virulent and attenuated strains), and cloacal swabs from clinically healthy ducks were more suitable for detection than oral swabs. In conclusion, the PCR assay established in the present study can be used as a simple and effective method for the clinical screening of ducks that are latently infected with virulent strains of DPV and shedding virus, which can provide technical support for the elimination of duck plague from duck farms.

Duck plague virus pUL15 performs a nonspecial cleavage activity through its C terminal nuclease domain in vitro.

Duck plague virus (DPV), also known as anatid herpesvirus, is a double-stranded DNA virus and a member of α herpesvirus. DPV pUL15 is a homolog of herpes simplex virus 1 (HSV-1) pUL15, a terminase large subunit, and plays a key role in the cleavage and packaging of the viral concatemeric genome. However, the sequence similarity between DPV pUL15 and its homologs is low, and it is not sure if DPV pUL15 has the potential to cleave the concatemeric genome as same as its homologs. Here, we expressed the C terminal domain of DPV pUL15 to explore the nuclease function of DPV pUL15. The main results showed that (Ⅰ) DPV pUL15 C-terminal domain possesses nonspecific nuclease activity and lacks the DNA binding ability. (Ⅱ) DPV pUL15 nuclease activity needs to coordinate with divalent metal ions and tends to be more active at high temperatures. (Ⅲ) Even though the structure of DPV pUL15 nuclease domain is relatively conserved, the mutations of conserved amino acids on the nuclease domain do not significantly inhibit the nuclease activity.

Zip Nucleic Acid-Based Genomagnetic Assay for Electrochemical Detection of microRNA-34a.

Zip nucleic acid (ZNA)-based genomagnetic assay was developed herein for the electrochemical detection of microRNA-34a (miR-34a), which is related to neurological disorders and cancer. The hybridization between the ZNA probe and miR-34a target was performed in the solution phase; then, the resultant hybrids were immobilized onto the surface of magnetic beads (MBs). After magnetic separation, the hybrids were separated from the surface of MBs and then immobilized on the surface of pencil graphite electrodes (PGEs). In the case of a full-match hybridization, the guanine oxidation signal was measured via the differential pulse voltammetry (DPV) technique. All the experimental parameters that influenced the hybridization efficiency (i.e., hybridization strategy, probe concentration, hybridization temperature, etc.) were optimized. The cross-selectivity of the genomagnetic assay was tested against two different miRNAs, miR-155 and miR-181b, individually as well as in mixture samples. To show the applicability of the ZNA-based genomagnetic assay for miR-34a detection in real samples, a batch of experiments was carried out in this study by using the total RNA samples isolated from the human hepatocellular carcinoma cell line (HUH-7).

Dual-mode immunosensor based on Cu-doped Mo2C nanosheets as signal labels.

A method for detecting of Carcinoembryonic antigen(CEA) with improved accuracy is urgently needed. In this work, a dual-mode immunosensor for accurate detection of CEA was fabricated, which used a Cu-doped Mo2C co-catalyst as an enhancer. Especially, Cu-doped Mo2C presents a strong different pulse voltammetry (DPV) signal for the electron transfer between Cu2+ and Cu+, without the addition of K3[Fe(CN6)] and other electron transfer mediators, but also shows high electrocatalytic activity towards H2O2 redox reactions. So that detection sensitivity of the chronoamperometry (CA) was enhanced. Furthermore, characterized by excellent conductivity, highly ordered pore distribution and great surface area, Ti3C2 Mxenes can be effective in promoting electron transfer and loading a large number of AuNPs. In the meantime, AuNPs can also immobilize CEA-Ab1 through Au-N bonds. Based on a Cu-Mo2C-Au dual-signal indicator, Ti3C2 Mxene-Au as the matrix, the immunsosensor was developed to achieve dual-signal detection of CEA. Satisfactory detection ranges (1 fg.mL-1 to 40 ng.mL-1) were obtained with limits of detection of 0.33 fg.ml-1 (DPV) and 1.67 fg.ml-1 (CA), respectively. Therefore, the prepared electrochemical immunosensor has good application prospects for the detection of CEA.

Sensitive electrochemical detection of polymorphisms in IL6 and TGFß1 genes from ovarian cancer DNA patients using EcoRI and DNA hairpin-modified gold electrodes.

Two electrochemical bioplatforms were prepared based on thiolated hairpin DNA probes tethered to AuNP-modified screen-printed electrodes to detect T > G and T > C polymorphisms, namely rs1880269 and rs1800469, present the interleukin-6 (IL6) and transforming growth factor ß1 (TGFß1) genes. The electrochemical readout was ensured by the detection of the double-stranded DNA using methylene blue as a redox probe after treatment by EcoRI restrictase. The main parameters influencing the analytical response such as the thiolated DNA probe concentration, incubation time with electrode, DNA hybridization time, EcoRI enzyme load, and its cleavage time were optimized based on the current intensity and signal-to-blank (S/B) ratio as selection criteria. Using spiked buffer solutions, the IL6 and TGFß1 E-bioplatforms display wide ranges of linearity (1 × 102-1 × 108 fM and 5 × 101-1 × 105 fM, respectively) and limits of detection (47.9 fM and 16.6 fM, respectively). The two bioelectrodes have also good discrimination toward 1-mismatched, two mismatched, and non-complementary sequences, when they were used 30-fold higher than the target sequences. More importantly, the two bioplatforms successfully detected the single nucleotide polymorphisms (SNPs) in scarcely diluted genomic DNA, collected from 52 donors, and showed they can reliably distinguish between heterozygous (TG and TC genotypes) and homozygous (GG and CC genotypes) patients with  respect to the control subjects (TT genotype), where the differences are statistically highly significant (p-value < 0.0001). Thus, the designed devices could be used to conduct large cohort studies targeting these mutations or extended to other SNPs.

Type 1 diabetes mellitus and SARS-CoV-2 in pediatric and adult patients - Data from the DPV network.

BACKGROUND: Data on patients with type 1 diabetes mellitus (T1DM) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections are sparse. This study aimed to investigate the association between SARS-CoV-2 infection and T1DM. METHODS: Data from the Prospective Diabetes Follow-up (DPV) Registry were analyzed for diabetes patients tested for SARS-CoV-2 by polymerase chain reaction (PCR) in Germany, Austria, Switzerland, and Luxembourg during January 2020-June 2021, using Wilcoxon rank-sum and chi-square tests for continuous and dichotomous variables, adjusted for multiple testing. RESULTS: Data analysis of 1855 pediatric T1DM patients revealed no differences between asymptomatic/symptomatic infected and SARS-CoV-2 negative/positive patients regarding age, new-onset diabetes, diabetes duration, and body mass index. Glycated hemoglobin A1c (HbA1c) and diabetic ketoacidosis (DKA) rate were not elevated in SARS-CoV-2-positive vs. -negative patients. The COVID-19 manifestation index was 37.5% in individuals with known T1DM, but 57.1% in individuals with new-onset diabetes. 68.8% of positively tested patients were managed as outpatients/telemedically. Data analysis of 240 adult T1MD patients revealed no differences between positively and negatively tested patients except lower HbA1c. Of these patients, 83.3% had symptomatic infections; 35.7% of positively tested patients were hospitalized. CONCLUSIONS: Our results indicate low morbidity in SARS-CoV-2-infected pediatric T1DM patients. Most patients with known T1DM and SARS-CoV-2 infections could be managed as outpatients. However, SARS-CoV-2 infection was usually symptomatic if it coincided with new-onset diabetes. In adult patients, symptomatic SARS-CoV-2 infection and hospitalization were associated with age.