Determination of carcinoembryonic antigen (CEA) by label-free electrochemical immunosensor using functionalized boron nitride nanosheets

In this study, a simple, specific and sensitive immunosensor for CEA detection was prepared based on BN nanosheets. Lewis acid-base interaction was sufficient for the immobilization of anti-CEA used as an antibody on the electrode surface without an activation agent. This immunosensor could be used for CEA determination without the need to use any label or secondary antibody. With its epedance-based recognition mechanism, this immunosensor offered a low LOD value of 0.017 ng/mL and a wide measurement range of 0.1-500 ng/mL and could be used for a long time. The analytical performance of this immunosensor is higher than the biosensors prepared in the literature. Compared to commercially available kits, it is attractive because it is cheap, simple and analyzes in a short time. This immunosensor, which has high selectivity against CEA in the presence of competitive agents in commercial human serum, has a high potential for clinical applications.

Preparation of PEGylated uricase attached magnetic nanowires and application for uric acid oxidation

The present study aims to immobilize the uricase enzyme on magnetic nanowires and to examine its potential for use in the treatment of gout. For this, Au/Ni/Au nanowires were synthesized using a polycarbonate membrane template by the sequential electrodeposition of Au, Ni, and Au, respectively. The uricase enzyme was covalently attached to these nanowires and was also coated with PEG. Optimum enzymatic conditions, kinetic parameters, thermal, storage, and operational stability were determined by performing enzymatic activity tests of free and immobilized uricase. Additionally, the efficacy of both enzyme preparations in artificial human serum and the presence of protease was also investigated. Experimental results showed that immobilized uricase showed higher stability than free uricase in all studied conditions. The potential of immobilized uricase to oxidize uric acid in artificial serum was also investigated and it was found that immobilized preparation demonstrated approximately 6 times higher activity than that of the free enzyme. The results of this study showed that uricase-attached nanowires oxidized uric acid effectively and are promising in the treatment of gout.

Inulinase Immobilized Lectin Affinity Magnetic Nanoparticles for Inulin Hydrolysis

In this presented paper, concanavalin A-modified cysteine-functionalized Fe₃O₄/Ag core/shell magnetic nanoparticles were synthesized and used as a support material for inulinase enzyme, which has been intensively used for the preparation of high-fructose syrup by hydrolyzing inulin. Inulinase adsorption capacity of Con A-functionalized Ag-coated magnetic nanoparticles was optimized by changing medium pH, temperature, and initial inulinase concentration, and maximum inulinase adsorption capacity was found to be 655.32 mg/g nanoparticle by using 1.00 mg/mL of inulinase solution in pH 3.0 buffer system at 25 °C. Finally, efficient inulin degradation capacity of the inulinase immobilized magnetic nanoparticles was demonstrated by TLC studies and released fructose amount was determined as 0.533 mg/mL only within the 5 min of hydrolysis. This newly developed hydrolysis strategy holds considerable promise to produce high-fructose syrup in many industries.