Salicylaldehyde functionalized chitosan for electrochemical sensitive sensor: Simultaneous determination of catechol and hydroquinone

Voltametric Sensor Based on Magnetic Chitosan Acetylindole-Based Nanocomposite for the Determination of Sulfamethazine

Sulfamethazine (SMZ), a persistent antibiotic, is frequently detected in drinking water and milk. For this reason, our research aimed to develop a novel electrochemical sensor based on a magnetic nanocomposite supported on chitosan modified by 3-acetylindole through the formation of chitosan acetylindole Schiff base (Chs-Aci). The objective was to detect extremely low concentrations of SMZ in milk. The synthesized nanocomposites were characterized by various techniques, including FT-IR, XRD, EDX, SEM, and TEM. To enhance the electrocatalytic efficiency for sensitive SMZ detection in food samples, a magnetic chitosan acetylindole nanocomposite (M-Chs-Aci) was employed as a modifier for a carbon paste electrode (CPE). The electrochemical measurements revealed that the M-Chs-Aci/CPE exhibits good electrocatalytic performance compared to a bare CPE. Moreover, low detection limit, repeatability, and stability were achieved at 0.021 μM, 3.83%, and 94.87%, respectively. Finally, the proposed M-Chs-Aci/CPE proved to be highly effective in detecting SMZ in milk samples. The obtained findings paved the way for the effective usability of M-Chs-Aci/CPE as a sensor for detecting SMZ in real samples, with acceptable recoveries of 95%-98.87%.

The Impact of Adding Chitosan Nanoparticles on Biofilm Formation, Cytotoxicity, and Certain Physical and Mechanical Aspects of Directly Printed Orthodontic Clear Aligners

Aligner treatment is associated with bacterial colonization, leading to enamel demineralization. Chitosan nanoparticles have been demonstrated to have antibacterial properties. This in vitro study aims to determine the effect of adding chitosan nanoparticles to directly 3D-printed clear aligner resin with regard to antibiofilm activity, cytotoxicity, degree of conversion, accuracy, deflection force, and tensile strength. Different concentrations (2%, 3%, and 5% w/w) of chitosan nanoparticles were mixed with the clear resin, and the samples were then 3D printed. Additionally, the thermoforming technique for aligner manufacturing was utilized. The obtained specimens were evaluated for antibiofilm activity against Streptococcus mutans bacteria and cytotoxicity against L929 and 3T3 cell lines. Additionally, Fourier transform infrared spectroscopy via attenuated total reflection analysis was used to assess the degree of conversion. Geomagic Control X software was utilized to analyze the accuracy. In addition, the deflection force and tensile strength were evaluated. The results indicated a notable reduction in bacterial colonies when the resin was incorporated with 3 and 5% chitosan nanoparticles. No significant changes in the cytotoxicity or accuracy were detected. In conclusion, integrating biocompatible chitosan nanoparticles into the resin can add an antibiofilm element to an aligner without compromising the material's certain biological, mechanical, and physical qualities at specific concentrations.