An affordable label-free ultrasensitive immunosensor based on gold nanoparticles deposited on glassy carbon electrode for the transferrin receptor detection.

In recent decades, there has been a concerning and consistent rise in the incidence of cancer, posing a significant threat to human health and overall quality of life. The transferrin receptor (TfR) is one of the most crucial protein biomarkers observed to be overexpressed in various cancers. This study reports on the development of a novel voltammetric immunosensor for TfR detection. The electrochemical platform was made up of a glassy carbon electrode (GCE) functionalized with gold nanoparticles (AuNPs), on which anti-TfR was immobilized. The surface characteristics and electrochemical behaviors of the modified electrodes were comprehensively investigated through scanning electron microscopy, XPS, Raman spectroscopy FT-IR, electrochemical cyclic voltammetry and impedance spectroscopy. The developed immunosensor exhibited robust analytical performance with TfR fortified buffer solution, showing a linear range (LR) response from 0.01 to 3000 µg/mL, with a limit of detection (LOD) of 0.01 µg/mL and reproducibility (RSD <4 %). The fabricated sensor demonstrated high reproducibility and selectivity when subjected to testing with various types of interfering proteins. The immunosensor designed for TfR detection demonstrated several advantageous features, such as being cost-effective and requiring a small volume of test sample making it highly suitable for point-of-care applications.

Brace-related Stress and Quality of Life Parameters between Chêneau and Boston Braces: A Cross-sectional Comparative Study on Adolescent Idiopathic Scoliosis in Saudi Arabia.

OBJECTIVE: Adolescent idiopathic scoliosis (AIS) is the most prevalent spinal deformity affecting healthy children. Although AIS typically lacks symptomatic manifestations, its resultant deformities can affect patients' quality of life (QoL). Evaluating QoL and stress levels is crucial in determining the optimal brace type for AIS patients; however, research comparing the effectiveness of different brace types in this regard is lacking. Therefore, this study aimed to evaluate the impact of Boston versus Chêneau braces on QoL and stress levels in AIS patients. METHODS: This cross-sectional study was conducted at a medical institution in Riyadh, Saudi Arabia, involving 52 eligible patients selected through stratified random sampling based on type of brace as the main stratum. The inclusion criteria were idiopathic scoliosis, age ≥ 10 years, bracing for at least 3 months, and no history of cancer. QoL was evaluated according to the revised Scoliosis Research Society 22-item questionnaire (SRS-22r) and stress levels according to the eight-item Bad Sobernheim stress questionnaire (BSSQ-Brace). Independent-sample t-tests were used to compare brace-related QoL and stress level according to participants' sex and brace type. RESULTS: Overall, 32 participants were treated with Boston braces (seven men and 25 women), with a median (IQR) age of 11.00 years (10.00-13.00), and 20 participants were treated with Chêneau braces (three men, 17 women), with a median (IQR) age of 12.50 years (10.00-14.25). The total SRS-22 score was not significantly different between the brace groups (p = 0.158). However, patients in the Boston brace group reported significantly higher satisfaction levels (median = 4.00, IQR = 3.50-4.50) than did those in the Chêneau brace group (median = 3.25, IQR = 2.38-4.13, p = 0.013, moderate effect size = 0.345, 95% CI = 0.060 to 0.590). Furthermore, the BSSQ-brace total score was significantly higher in the Boston brace group (median = 9.00, IQR = 8.00-12.00) than in the Chêneau brace group (median = 7.50, IQR = 4.75-10.00, p = 0.007, moderate effect size = 0.376, 95% CI = 0.130 to 0.590), indicating higher stress levels in the Chêneau brace group. CONCLUSION: The QoL in AIS patients undergoing brace treatment was comparable across groups. Nonetheless, patients who used Chêneau braces experienced higher stress levels and lower treatment satisfaction rates than did those who used Boston braces. These findings can inform clinical decisions regarding prescription of bracing types and highlight the need for further in-depth research.

Synthesis of carbon nanotubes-chitosan nanocomposite and immunosensor fabrication for myoglobin detection: An acute myocardial infarction biomarker.

The use of single-walled carbon nanotubes (SWCNTs) in biomedical applications is limited due to their inability to disperse in aqueous solutions. In this study, dispersed -COOH functionalized CNTs with N-succinylated chitosan (CS), greatly increasing the water solubility of CNTs and forming a uniformly dispersed nanocomposite solution of CNTs@CS. Coupling reagent EDC/NHS was used as a linker with the -COOH groups present on the N-succinylated chitosan which significantly improved the affinity of the CNTs for biomolecules. Myoglobin (Mb) is a promising biomarker for the precise assessment of cardiovascular risk, type 2 diabetes, metabolic syndrome, hypertension and several types of cancer. A high level of Mb can be used to diagnose the mentioned pathogenic diseases. The CNTs@CS-FET demonstrates superior sensing performance for Mb antigen fortified in buffer, with a wide linear range of 1 to 4000 ng/mL. The detection limit of the developed Mb immunosensor was estimated to be 4.2 ng/mL. The novel CNTs@CS-FET immunosensor demonstrates remarkable capability in detecting Mb without being affected by interferences from nonspecific antigens. Mb spiked serum showed a recovery rate of 100.262 to 118.55 % indicating great promise for Mb detection in clinical samples. The experimental results confirmed that the CNTs@CS-FET immunosensor had excellent selectivity, reproducibility and storage stability.

Fabrication of an affordable and sensitive corticosteroid-binding globulin immunosensor based on electrodeposited gold nanoparticles modified glassy carbon electrode.

Herein, we fabricated an ultrasensitive electrochemical immunosensor for the quantitative detection of corticosteroid-binding globulin (CBG). CBG is a protein that regulates glucocorticoid levels and is an important biomarker for inflammation. A decrease in CBG levels is a key biomarker for inflammatory diseases, such as septic shock. To enhance the electrochemical performance and provide a large surface area for anti-CBG immobilization, we functionalized the glassy carbon electrode surface with AuNPs. Electrochemical characterization methods including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to examine the construction of the fabricated immunosensor. The electrochemical signal demonstrated a remarkable sensitivity to the CBG antigen, with a detection range from 0.01 to 100 µg/mL and a limit of detection of 0.012 µg/mL, making it suitable for both clinical and research applications. This label-free immunosensor offers significant advantages, including high sensitivity, low detection limits and excellent selectivity, making it a promising tool for detecting CBG in complex biological samples. Its potential applications include early disease diagnosis, treatment monitoring and studying CBG-related physiological processes.