Carbon Nanofiber-Ionic Liquid Nanocomposite Modified Aptasensors Developed for Electrochemical Investigation of Interaction of Aptamer/Aptamer–Antisense Pair with Activated Protein C

Selective and sensitive detection of human activated protein C (APC) was performed herein by using carbon nanofiber (CNF) and ionic liquid (IL) composite modified pencil graphite electrode (PGE) and electrochemical impedance spectroscopy (EIS) technique. A carbon nanomaterial-based electrochemical aptasensor was designed and implemented for the first time in this study for the solution-phase interaction of DNA-Apt with its cognate protein APC as well as APC inhibitor aptamer–antidote pair. The applicability of this assay developed for the determination of APC in fetal bovine serum (FBS) and its selectivity against different proteins (protein C, thrombin, bovine serum albumin) was also examined. CNF-IL modified aptasensor specific to APC provided the detection limit as 0.23 μg/mL (equal to 3.83 nM) in buffer medium and 0.11 μg/mL (equal to 1.83 nM) in FBS. The duration of the proposed assay from the point of electrode modification to the detection of APC was completed within only 55 min

Amperometric immunosensor developed for sensitive detection of SARS-CoV-2 spike S1 protein in combined with portable device

In this present study, an amperometric immunosensor was developed based on disposable screen-printed carbon electrode (SPCE) for specific and sensitive detection of SARS-CoV-2 S1 protein. Anti-SARS-CoV-2 S1 monoclonal antibody was firstly immobilized onto the electrode surface. Then, the sandwich complex was formed by addition of S1 protein, secondary antibody and HRP-IgG, respectively. Chronoamperometry measurements were done in the presence of TMB mediator and the detection of SARS-CoV-2 S1 protein was performed by using 10 mu L sample. The limit of detection (LOD) was found to be 0.19 ng/mL (equals to 24.7 amol in 10 mu L sample) in the linear range of 0.5-10 ng/mL obtained in buffer medium. The applicability of this assay was investigated in the linear range of 0.5-3 ng/mL S1 protein in artificial saliva medium with the LOD as 0.13 ng/mL (equals to 16.9 amol in 10 mu L sample). The selectivity study was examined in the presence of Hemagglutinin antigen (HA) in both mediums; buffer and artificial saliva while resulting with the successful discrimination between S1 protein and HA. The one of ultimate goals of our study is to present the possible implementation of this assay to point of care (POC) analysis. Under this aim, this assay was performed in combination with a portable device that is the commercial electrochemical analyzer. Amperometric detection of S1 protein in the range of 0.5-5 ng/mL was also successfully performed in artificial saliva medium with a resulting LOD as 0.15 ng/mL (equals to 19.5 amol in 10 mu L sample). In addition, a selectivity study was similarly carried out by portable device.Turkish Scientific and Technological Research Council (TUEBITAK, Turkey)A.E acknowledges the financial support from Turkish Scientific and Technological Research Council (TUEBITAK, Turkey) (Project No. 120S419) as the Project Investigator, and she also would like to express her gratitude to the Turkish Academy of Sciences (TUEBA, Turkey) as an Principal member for its partial support. H.S, E.Y and M.M acknowledge project scholarship by TUEBITAK (Project No. 120S419) . The authors acknowledge BioRender.com for aid in creating partially some graphical elements in graphical abstract, Figs. 1 and 2

Impedimetric Detection Based on Label-Free Immunoassay Developed for Targeting Spike S1 Protein of SARS-CoV-2

After the COVID-19 pandemic started all over the world, great importance was placed on the development of sensitive and selective bioanalytical assays for the rapid detection of the highly pathogenic SARS-CoV-2 virus causing COVID-19 disease. In this present work, an impedimetric immunosensor was developed and applied for rapid, reliable, sensitive and selective detection of the SARS-CoV-2 S1 protein. To detect the SARS-CoV-2 virus, targeting of the spike S1 protein was achieved herein by using S1 protein-specific capture antibody (Cab-S1) immobilized screen-printed electrode (SPE) in combination with the electrochemical impedance spectroscopy (EIS) technique. With the impedimetric immunosensor, the detection limit for S1 protein in buffer medium was found to be 0.23 ng/mL (equal to 23.92 amol in 8 mu L sample) in the linear concentration range of S1 protein from 0.5 to 10 ng/mL. In the artificial saliva medium, it was found to be 0.09 ng/mL (equals to 9.36 amol in 8 mu L sample) in the linear concentration range of S1 protein between 0.1 and 1 ng/mL. The selectivity of the impedimetric immunosensor toward S1 protein was tested against influenza hemagglutinin antigen (HA) in the buffer medium as well as in artificial saliva.Scientific and Technological Research Council of Turkey [120S419]This research was funded by Scientific and Technological Research Council of Turkey grant number TUB.ITAK Project No. 120S419

Development of single-use thin film electrodes based on Zn2SnO4 on In2O3: SnO2 substrates with their biosensing applications

Dopamine (DA) has a significant impact on the emergence and treatment of certain diseases (e.g., Alzheimer's and Parkinson's diseases). Therefore, monitoring of DA is important, and using biosensors is a favorable option instead of time-consuming and expensive conventional methods. In biosensor manufacturing, thin films have become a rapidly emerging field. In this study, a non-enzymatic electrochemical biosensor based on thin film electrodes is developed for monitoring DA levels. The thin film electrodes (ZTO/ITO) are developed by deposition of Zn2SnO4 (ZTO) on In2O3:SnO2 (ITO) substrates by magnetron sputtering. 3-aminopropyltriethoxysilane (APTES) is used to modify the surface of these electrodes. Physical, optical, and structural properties of the electrodes are determined by applying surface profilometry, UV-VIS-NIR spectrophotometry, X-ray diffraction (XRD), and scanning electron microscopy (SEM) measurements. According to these measurements, it has been observed that the ZTO/ITO combination has a higher optical transmission value than the bare ITO, depending on the deposition time and the oxygen concentration used during ZTO deposition. In addition, the ITO thin film has a crystalline structure, while the ZTO thin film has an amorphous structure and both thin films have a good surface morphology. As electrochemical analysis, cyclic voltammetry (CV), electrochemical impedance spec-troscopy (EIS), and differential pulse voltammetry (DPV) measurements are performed. As a result of CV and EIS measurements, a remarkable change (63.54%) was observed after applying APTES modification onto the surface of ZTO/ITO electrode, and the ones obtained by DPV showed successful detection of DA by APTES modified ZTO/ITO. In addition, the experiments in the presence of interferences such as ascorbic acid (AA), uric acid (UA), bovine serum albumin (BSA), and fish sperm double-stranded DNA (fsDNA) show that the electrodes can be successfully applied for voltammetric determination of DA. The detection limit of DA was estimated to be 0.013 mu M in the range of DA between 0.1 and 1 mu M, and sensitivity was calculated and found to be 11.057 mu A mu g(-1) mL cm(-2), which means ZTO/ITO electrodes have a good sensitivity.This article is based on the findings within the scope of master's thesis of Betuel Yurttas,. A.E. would like to express her gratitude to the Turkish Academy of Sciences (TUEBA) as a principal member for its partial support. The authors acknowledge Research and Application Center for Quantum Technologies (RACQUT) for the facilities of IZTECH they provided for this study.Turkish Academy of Sciences (TUEBA

The Seroprevalence of Toxoplasmosis Among Reproductive-Age Women in Ankara a Central Anatolian City Turkey

OBJECTIVE: The objective of this study is to investigate seroprevalence of toxoplasmosis among reproductive-age women in rural and urban areas in Ankara, a central Anatolian city in Turkey. STUDY DESIGN: A total of 321 reproductive-age women from Karagedik, rural area and 1732 from Gazi university hospital, urban area, have been included in this study. Rural and Gazi university hospital parts of the study have been conducted December 1997 - May 1998 and January 1998- December 2005 respectively. All women were screened for toxoplasma Ig G antibodies in their serum. Samples with >6 IU were considered positive for Toxoplasma gondii immunoglobulin G antibodies. RESULTS: Seropositivity in rural and urban areas was 44.7% and 40.7% respectively. There was no statistically significant difference between two groups. Higher seropositivity has been observed in both groups as the age increases. However, in both study groups logistic regression revealed that seropositivity was not significantly associated with age, education, and occupation. CONCLUSIONS: Since high rate of prevalence and the half of the cases have been acquired during reproductive years, it seems to be beneficial to screen all pregnant women during pregnancy in Ankara, Turkey

Effect of nitric oxide synthase inhibitors in acute lung injury due to blunt lung trauma in rats

WOS: 000455260600010Background: This study aims to investigate the effects of blunt lung trauma performed in experimental rat model on lung tissue and blood as well as proinflammatory cytokines, oxidant-antioxidant enzymes and histopathological parameters after Ngamma-nitro-L-arginine methyl ester and N-iminoethyl-L-ornithine administration. Methods: The study included 50 adult male Wistar albino rats (weighing 350 to 400 g). Rats were randomly allocated into four groups. Except in the control, moderate-level pulmonary contusion was created in all other groups. Intraperitoneal saline solution was performed in groups 1 and 2, 25 mg.kg(-1) Ngamma-nitro-L-arginine methyl ester in group 3, and 20 mg. kg(-1) N-iminoethyl-L-ornithine in group 4. Blood and lung tissues were studied biochemically and histopathologically. Results: Best outcomes were recorded statistically significantly in groups with administration of Ngamma-nitro-L-arginine methyl ester and N-iminoethyl-L-ornithine when malondialdehyde response, mucous and histopathological values were examined. Significant improvement was detected in superoxide dismutase values in the group with administration of competitive nitric oxide synthase inhibitor Ngamma-nitro-L-arginine methyl ester. Nitric oxide values were substantially decreased in N-iminoethyl-L-ornithine group, while no significance was detected. Conclusion: Free oxygen radicals and lipid peroxidation played a role in pulmonary contusion after blunt lung trauma. According to biochemical and histopathological outcomes, effects of inflammation were decreased and protective effects were formed with administration of both Ngammanitro-L-arginine methyl ester and N-iminoethyl-L-ornithine

An interim analysis of the Turkish Myeloma Registry among patients who have received up to two lines of therapy

Background To investigate the demographics and treatment details of the myeloma patients who were diagnosed and followed up in Turkey and received up to two lines of therapy. Methods Patients who were recorded on the database of Turkish Myeloma Registry project were included in this study if they had only received one or two lines of therapy. Demographics, patient, and disease related parameters both at the time of diagnosis and at the follow up and treatment outcomes were presented