Innovative Surface Designs for Sensing Applications

An essential problem in the field of advanced sensing systems is the search for innovative surfaces that can combine an effective immobilization of biomolecules or behave directly as an enzyme mimic with increased analytical performance [...

Fullerene-based mimics of enhanced acetylcholine detection for the diagnosis of Alzheimer's disease

The design of sensitive and cost-effective enzyme-free sensor systems for the effective electrooxidation of acetylcholine (ACh) plays a key role in following up on Alzheimer's disease. We report a fullerenzyme-based catalyst (F-HS) for the electrochemical detection of ACh that mimics enzymatic active sites using multifunctional self-assembled nanostructures. As a proof-of-concept, histidine and serine amino acid-based functionalization of fullerenzymes was used, along with embedded nickel ions (F-HS-Ni), which tend to coordinate with the nitrogen of the imidazole ring of the histidine moiety. Further, the electrode modifier properties of the resulting material were examined for sensor applications. Enhanced cyclic voltammetry and chronoamperometric measurements affirmed that the F-HS-Ni material displayed the most prominent activity for the electrocatalytic oxidation of ACh, allowing an amperometric response in a linear range of ACh concentrations of 20–6000 μM with a low detection limit of 8.01 μM. Furthermore, the platform allows for the detection of ACh with a good rate of recovery in human serum samples, offering a good potential method for the quick detection and diagnosis of Alzheimer's

Synthesis and design of functional fullerenol-based electrochemical nanobiosensor to examine the inhibition effects of anti-Alzheimer drug active pyridostigmine on acetylcholinesterase

Glutamic acid functionalized fullerenol (F-Glu) based electrochemical AChE enzyme biosensor (GE/F-Glu/AChE) was utilized for the detection of acetylthiocholine chloride and pyridostigmine for the first time. The performance of the biosensor was validated, including recovery studies on human serum and urine, to assess method accuracy. The GE/F-Glu/AChE biosensor exhibited a Limit Of Detection (LOD) of 0.0004 mM and a Limit Of Quantification (LOQ) of 0.001 mM for acetylthiocholine chloride detection. Morphological and electrochemical characterizations of the biosensors were conducted using FT-IR, FE-SEM, AFM, CV, and EIS techniques. Furthermore, the biosensor was employed to investigate the inhibition of AChE activity by Pyridostigmine (PDT), with an IC50 value of 1.01 mM PDT. The inhibitory effect of PDT on the biosensor was explored in synthetic human serum, synthetic human urine, and pharmaceutical formulations containing PDT's active ingredient under optimal biosensor conditions

Polymerization and biosensor application of water soluble peptide-SNS type monomer conjugates

A simple and efficient approach for the preparation of a biosensing platform was developed based on newly designed peptide-SNS type monomer conjugates. The approach involves the electrochemical polymerization of the peptide-SNS type monomer on the electrode surface. To synthesize the peptide bearing monomers, the SNS-type monomer having a carboxylic acid functional group was anchored to the C-terminal of the peptide by solid phase peptide synthesis via coupling reagents. Utilization of peptides to increase the solubility of the monomers was first investigated in this report. The obtained monomers, soluble in water, were fully characterized by spectral analyses and utilized as matrices for biomolecule attachment. Polymerization of monomers in water has the potential to provide an alternative process for the electrochemical preparation of the polymers in aqueous media, without using any organic solvent. Under the optimized conditions, the biosensor responded to the target analyte, glucose, in a strikingly selective and sensitive manner, and showed promising feasibility for the quantitative analysis of glucose in beverages

Comparative cell adhesion properties of cysteine extended peptide architectures

WOS: 000368193500020This study presents the comparative cell attachment investigation of TAT and well-known RGD peptide modified surfaces. Initially, cysteine containing arginine-glycine-aspartic acid (RGD) and TAT peptides, a class of cell penetration peptides, were synthesized. Gold film coated indium tin oxide (gold/ITO) surfaces were coated with RGD and TAT peptides and used for cell culture applications. Thiol groups on the peptides provide post-modification of the surface. The efficient bonding of the peptides with the modified surface brings proper attachment of the cells. The peptide modified surfaces were tested for adhesion of several cell lines such as monkey kidney epithelial cell (Vero), human cervical carcinoma cell (HeLa), human glioblastoma cell (U87-MG) and human immortalized skin keratinocyte cell (HaCaT) lines. These cells were cultured on RGD and TAT modified gold/ITO surfaces. Cell imaging studies were performed on these surfaces using fluorescence microscopy technique. Scanning electron microscopy (SEM), atomic force microscopy (AFM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and contact angle measurements were carried out for the surface characterization. The results indicate that the RGD and TAT modified surfaces exhibited better cell adhesion. Therefore, besides RGD as a well-known adhesion peptide, TAT functionalized substrates were found to be efficient bio-sensing candidates for further studies

Surface Engineering of MXene and Functional Fullerenols for Cancer Biomarker ‘eIF3d’

Selective and sensitive detection of eIF3d (eukaryotic translation initiation factor 3 complex, subunit D), a protein biomarker, is of fundamental significance for the diagnosis of various cancers. Here, we report an electrochemical sensor based on MXene and aspartic acid-functionalized fullerenol (F-Asp) for the biosensing of eIF3d. To construct such an innovative sensing platform, MXene was first synthesized, followed by the convenient functionalization of fullerenol with aspartic acid groups (F-Asp) through hydroxylation and activation of fullerenes. Finally, a bioplatform was created for eIF3d sensing by modifying the graphite electrode (GE) surface with MXene and F-Asp, followed by surface functionalization with anti-eIF3d antibody via EDC/NHS chemistry. Detailed electrochemical and analytical material characterization methods were utilized after each surface modification step. Notably, the surface-engineered MXene:F-Asp showed superior electrochemical features. The sensor’s response to eIF3d was achieved in the linear range of 10 to 250 ng/mL, with a detection limit of 0.14 ng/mL. The selectivity of the sensor was assessed by monitoring its response to eIF3d in the presence of a variety of interfering compounds. Analysis of eIF3d was effectively performed in synthetic serum samples. The promising electrochemical sensing properties of the designed sensor suggest great potential for various real-time health monitoring applications

Respiratory functions in the follow-up of children with COVID-19 infection

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Childhood interstitial lung disease in Turkey: first data from the national registry

Abstract: The childhood interstitial lung diseases (chILD) Turkey registry (chILD-TR) was established in November 2021 to increase awareness of disease, and in collaboration with the centers to improve the diagnostic and treatment standards. Here, the first results of the chILD registry system were presented. In this prospective cohort study, data were collected using a data‐entry software system. The demographic characteristics, clinical, laboratory, radiologic findings, diagnoses, and treatment characteristics of the patients were evaluated. Clinical characteristics were compared between two main chILD groups ((A) diffuse parenchymal lung diseases (DPLD) disorders manifesting primarily in infancy [group1] and (B) DPLD disorders occurring at all ages [group 2]). There were 416 patients registered from 19 centers. Forty-six patients were excluded due to missing information. The median age of diagnosis of the patients was 6.05 (1.3–11.6) years. Across the study population (n = 370), 81 (21.8%) were in group 1, and 289 (78.1%) were in group 2. The median weight z-score was significantly lower in group 1 (− 2.0 [− 3.36 to − 0.81]) than in group 2 (− 0.80 [− 1.7 to 0.20]) (p < 0.001). When we compared the groups according to chest CT findings, ground-glass opacities were significantly more common in group 1, and nodular opacities, bronchiectasis, mosaic perfusion, and mediastinal lymphadenopathy were significantly more common in group 2. Out of the overall study population, 67.8% were undergoing some form of treatment. The use of oral steroids was significantly higher in group 2 than in group 1 (40.6% vs. 23.3%, respectively; p = 0.040). Conclusion: This study showed that national registry allowed to obtain information about the frequency, types, and treatment methods of chILD in Turkey and helped to see the difficulties in the diagnosis and management of these patients. What is Known: • Childhood interstitial lung diseases comprise many diverse entities which are challenging to diagnose and manage. What is New: • This study showed that national registry allowed to obtain information about the frequency, types and treatment methods of chILD in Turkey and helped to see the difficulties in the diagnosis and management of these patients. Also, our findings reveal that nutrition should be considered in all patients with chILD, especially in A-DPLD disorders manifesting primarily in infancy