Glucose is one of the most important monosaccharides found in the food, as a part of more complex structures, which is a primary energy source for the brain and body. Thus, the monitoring of glucose concentration is more important in food and biological samples in order to maintain a healthy lifestyle. Herein, an electrochemical glucose biosensor was fabricated by immobilization of glucose oxidase (GOX) onto poly(3,4-ethylenedioxythiophene):4-sulfocalix [4]arene (PEDOT:SCX)/MXene modified electrode. For this purpose, firstly, PEDOT was synthesized in the presence of SCX (counterion) by the chemical oxidative method. Secondly, MXene (a 2D layered material) was synthesized by using a high-temperature furnace under a nitrogen atmosphere. After that, PEDOT:SCX/MXene (1:1) dispersion was prepared by ultrasonication which was later utilized to prepare PEDOT:SCX/MXene hybrid film. A successful formation of PEDOT:SCX/MXene film was confirmed by HR-SEM, Fourier transform infrared (FT-IR), and Raman spectroscopies. Due to the biocompatibility nature, successful immobilization of GOX was carried out onto chitosan modified PEDOT:SCX/MXene/GCE. Moreover, the electrochemical properties of PEDOT:SCX/MXene/GOX/GCE was studied through cyclic voltammetry and amperometry methods. Interestingly, a stable redox peak of FAD-GOX was observed at a formal potential of –0.435 V on PEDOT:SCX/MXene/GOX/GCE which indicated a direct electron transfer between the enzyme and the electrode surface. PEDOT:SCX/MXene/GOX/GCE also exhibited a linear response against glucose concentrations in the linear range from 0.5 to 8 mM. The effect of pH, sensors reproducibility, and repeatability of the PEDOT:SCX/MXene/GOX/GCE sensor were studied. Finally, this new biosensor was successfully applied to detect glucose in commercial fruit juice sample with satisfactory recovery.

In this study, for the first time, Phyllanthus Reticulatus fruit extract was utilized as a reducing agent in the synthesis of silver nanoparticles (Ag-NPs). For sample analysis, a number of approaches were employed. The synthesized Ag-NPs have a spherical shape and a homogeneous in size. The well-known crystal structure and optical energy absorption spectrum of Ag-NPs were respectively revealed by the XRD and UV-VIS analysis. This new method is simple and eco-friendly for producing silver and other noble metals in large quantities. The Ag-NPs modified glassy carbon electrode was prepared for nicotine oxidation which indicated that Ag NPs had the ability to enhance the electron transfer rate of the oxidation process. In 0.1 M phosphate buffer (pH of 7.4), a significant increase in the oxidation peak current of nicotine was observed at the modified electrode. Cyclic voltammetry, amperometry, and electrochemical impedance spectroscopy characterizations showed that Ag-NPs had better electrocatalytic performance toward nicotine (NIC) oxidation with good stability, and selectivity. This sensor showed a linear response with the concentration of NIC in the range of 2.5 to 105 μM. The limit of detection (LOD) was estimated to be 0.135 μM. The interference analysis was carried out on the Ag-NPs/GCE with various molecules like acetic acid, ascorbic acid, calcium chloride, glucose, magnesium chloride, urea, and uric acid. Hence, these molecules did not interfere with NIC detection, indicating a perfect selectivity of Ag-NPs/GCE. Moreover, the Ag-NPs/GCE sensor was effectively applied to detect NIC in a real-world sample (saliva) of a tobacco chewer. Furthermore, the Ag-NPs/GCE sensor exhibited very good stability and repeatability in human saliva samples. Finally, Ag-NPs/GCE was also successfully applied to detect spiked nicotine in saliva samples with high recovery value, indicating its high accuracy and effectiveness in NIC analysis.

High concentrations of nicotine (40 to 60 mg) are more dangerous for adults who weigh about 70 kg. Herein, we developed an electrochemical transducer using an MXene (Ti₃C₂Tx)/palladium hydroxide-supported carbon (Pearlman’s catalyst) composite (MXene/Pd(OH)₂/C) for the identification of nicotine levels in human sweat. Firstly, the MXene was doped with Pd(OH)₂/C (PHC) by mechanical grinding followed by an ultrasonication process to obtain the MXene/PHC composite. Secondly, XRD, Raman, FE-SEM, EDS and E-mapping analysis were utilized to confirm the successful formation of MXene/PHC composite. Using MXene/PHC composite dispersion, an MXene/PHC composite-modified glassy carbon electrode (MXene/PHC/GCE) was prepared, which showed high sensitivity as well as selectivity towards nicotine (300 µM NIC) oxidation in 0.1 M phosphate buffer (pH = 7.4) by cyclic voltammetry (CV) and amperometry. The MXene/PHC/GCE had reduced the over potential of nicotine oxidation (about 200 mV) and also enhanced the oxidation peak current (8.9 µA) compared to bare/GCE (2.1 µA) and MXene/GCE (5.5 µA). Moreover, the optimized experimental condition was used for the quantification of NIC from 0.25 µM to 37.5 µM. The limit of detection (LOD) and sensitivity were 27 nM and 0.286 µA µM⁻¹ cm², respectively. The MXene/PHC/GCE was also tested in the presence of Na⁺, Mg²⁺, Ca²⁺, hydrogen peroxide, acetic acid, ascorbic acid, dopamine and glucose. These molecules were not interfered during NIC analysis, which indicated the good selectivity of the MXene/PHC/GCE sensor. In addition, electrochemical determination of NIC was successfully carried out in the human sweat samples collected from a tobacco smoker. The recovery percentage of NIC in the sweat sample was 97%. Finally, we concluded that the MXene/PHC composite-based sensor can be prepared for the accurate determination of NIC with high sensitivity, selectivity and stability in human sweat samples.

Alcohol is a dangerous substance causing global mortality and health issues, including mental health problems. Regular alcohol consumption can lead to depression, anxiety, cognitive decline, and increased risk of alcohol-related disorders. Thus, monitoring ethanol levels in biological samples could contribute to maintaining good health. Herein, we developed an electrochemical sensor for the determination of ethanol in human salivary samples. Initially, the tetra-chloroauric acid (HAuCl₄) was chemically reduced using sparfloxacin (Sp) which also served as a stabilizing agent for the gold nanoparticles (AuNPs). As-prepared Sp-AuNPs were comprehensively characterized and confirmed by UV-visible spectroscopy, X-ray diffraction, field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and elemental mapping analysis. The average particle size (~25 nm) and surface charge (negative) of Sp-AuNPs were determined by using dynamic light scattering (DLS) and Zeta potential measurements. An activated screen-printed carbon electrode (A-SPE) was modified using Sp-AuNPs dispersion, which exhibited greater electrocatalytic activity and sensitivity for ethanol (EtOH) oxidation in 0.1 M sodium hydroxide (NaOH) as studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). DPV showed a linear response for EtOH from 25 µM to 350 µM with the lowest limit of detection (LOD) of 0.55 µM. Reproducibility and repeatability studies revealed that the Sp-AuNPs/A-SPEs were highly stable and very sensitive to EtOH detection. Additionally, the successful electrochemical determination of EtOH in a saliva sample was carried out. The recovery rate of EtOH spiked in the saliva sample was found to be 99.6%. Thus, the incorporation of Sp-AuNPs within sensors could provide new possibilities in the development of ethanol sensors with an improved level of precision and accuracy.

Whitlockite (WH), a magnesium-enriched calcium phosphate mineral, is emerging as a promising biomaterial in bone tissue engineering due to its chemical similarity to natural bone and dual role in promoting osteogenesis and regulating bone resorption. Compared to conventional materials like hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), WH offers higher solubility, superior ion release (notably Mg²⁺), and enhanced bioactivity. This systematic review evaluates the in vivo efficacy of WH-based biomaterials in bone regeneration. Key outcomes include bone volume fraction (BV/TV), bone mineral density (BMD), osteogenic marker expression, and histological bone quality. A comprehensive search of PubMed, Web of Science, Google Scholar, and Cochrane Central was conducted up to March 2025. Eligible studies assessed WH-based materials in animal bone defect models with quantifiable regenerative outcomes. Two reviewers independently performed data extraction and quality assessment using the SYRCLE Risk of Bias tool. Meta-analysis was not feasible due to significant heterogeneity across models, scaffold types, and endpoints. Seventeen animal studies (rats, mice, rabbits) met inclusion criteria. WH was used in forms such as nanoparticles, granules, and scaffolds with polymers like chitosan and gelatin. WH consistently outperformed HA and β-TCP with up to a 2–6 % increase in BV/TV, BMD, and histological bone formation. Upregulation of ALP, OCN, RUNX2, and COL1 was observed. Doped WH variants and composites enhanced osteoinductive and angiogenic responses. No adverse effects were reported. WH demonstrates superior osteogenic and biocompatible properties over traditional calcium phosphates. Future standardized, long-term studies are needed to support clinical translation for orthopedic and dental bone regeneration.

Objective: The objective of this study was to evaluate the antimicrobial potential of nanocomposites containing vitamin K2, hydroxyapatite nanoparticles (nHAP), and chitosan (Chito)-coated dental implants against clinically relevant microbial strains.