High durability of food due to the flow cytometry proved antibacterial and antifouling properties of TiO2 decorated nanocomposite films

Design and characterization of a biosensor with lipase immobilized nanoparticles in polymer film for the detection of triglycerides

High levels of triglycerides in blood can harden and block the arteries increasing the risk of heart disease and strokes. Triglycerides are important constituents of oils and fats used in various foods. The triglyceride content in commercial preparations of oils is estimated using conventional methods. In the present study, an electrochemical biosensor with lipase immobilized novel conductive polymer film has been developed for estimating triglyceride content in a variety of products. The portable biosensor can bring down the detection costs dramatically and can be used for varied purposes. It is based on cyclic voltammetry and has a three-electrode configuration system. Glassy carbon electrode is functionalized with nanoparticles embedded in polyethyleneimine and lipase is immobilized using glutaraldehyde. The strategy increases the electrochemical conductance manifold and overcomes the hindrance to lipase posed by membranes as it is oriented on the outside of the membrane. Thus, it increases the sensitivity and selectivity of detection. Results of scanning electron microscopy and FT-IR spectroscopy were used for characterizing the electrode surface. Linear range of the electrode for triglycerides is 100-500 mg/dL. The sensor was used successfully to determine triglyceride content in several real samples and the average recovery values lie from 95.47 % to 101.05 %.

Green Synthesis of TiO2 Nanoparticles Using Natural Marine Extracts for Antifouling Activity

Titanium dioxide (TiO₂) nanoparticles were synthesized via a novel eco-friendly green chemistry approach using marine natural extracts of two red algae (Bostrychia tenella and Laurencia obtusa), a green alga (Halimeda tuna), and a brown alga (Sargassum filipendula) along with a marine sponge sample identified as Carteriospongia foliascens. X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis, X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) were employed to characterize the crystal structure, surface morphology, and optical properties of the synthesized nanoparticles. Each of the as-synthesized marine extract based TiO₂ nanoparticles was individually incorporated as an antifouling agent to form a newly fabricated marine paint formulation. The newly prepared formulations were applied on unprimed steel panels. A comparative study with a commercial antifouling paint (Sipes Transocean Coatings Optima) was carried out. After 108 days of the coated steel panels' immersion in the Eastern Harbour seawater of Alexandria-Egypt, the prepared paints using B. tenella and C. foliascens extracts demonstrated an excellent antifouling performance toward fouling organisms by inhibiting their settlement and controlling their adhesion onto the immersed panels. In contrast, heavy fouling with barnacles was observed on the surface of the coated panel with the commercial paint. The physicochemical parameters of the seawater surrounding the immersed coated panels were estimated to investigate the influence of the fabricated paint formulations. Interestingly, no effects of the immersed coated panels on the physicochemical characteristics of the surrounding seawater were observed. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO₂ nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO₂ nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents, which could be attributed to the small crystallite sizes of 22.86 and 8.3 nm, respectively, in addition to the incorporation of carbon in the crystal structure of the nanoparticles.