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.

Boron nitride nanosheet modified label-free electrochemical immunosensor for cancer antigen 125 detection.

In this presented study, a new boron nitride nanosheets modified label-free electrochemical immunosensors were prepared for early detection of cancer antigen 125 (CA125). To aim for, boron nitride (BN) nanosheets were synthesized by conventional sonication-assisted method and then characterized. BN nanosheets were used for the surface modification of the working electrode of the screen-printed electrode (SPE). Anti CA125 antibody was then directly immobilized onto the electrode surface due to its natural affinity towards BN nanosheets. Modified electrodes were blocked with BSA and finally protected with Nafion. The newly synthesized label-free immunosensor demonstrated good detection properties to CA125 with a linear range of 5-100 U and a detection limit of 1.18 U/mL. The developed immunosensor also showed excellent reproducibility, selectivity, and stability profiles. Additionally, this immunosensor was successfully used for the detection of CA125 in artificial human serum samples along with the interfering agents. Also, it is expected that the prepared immunosensor should carry the good potential for point-of-care diagnosis in real cases.

Immobilization of L-Asparaginase on Magnetic Nanoparticles for Cancer Treatment.

In this presented work, magnetic poly(HEMA-GMA) nanoparticles were synthesized, characterized, and used for immobilization of an anti-leukemic enzyme L-asparaginase. The average particle size of the synthesized magnetic nanoparticles was found to be as 117.5 nm. L-asparaginase was successfully immobilized onto the synthesized magnetic nanoparticles, and attached amount of L-asparaginase was found to be as 66.43 mg/g nanoparticle. The effects of the medium pH, temperature, and substrate concentration on the L-asparaginase activity were also tested. Optimum pH of the free and immobilized L-asparaginase was found to be as 7.5 and 6.5, respectively. Optimum temperature of the free L-asparaginase was 45 °C, while optimum temperature was shifted to 55 °C after immobilization onto the magnetic nanoparticles. Also, kcat value of free L-asparaginase (47,356 min-1) was calculated to be higher than that of immobilized L-asparaginase (497 min-1). Thermal stability of both asparaginase preparation was followed for 10 h, and at the end of the incubation time, free asparaginase almost lost its activity, while immobilized asparaginase protected 50% of its initial activity. Storage stabilities of free and immobilized asparaginase were also tested, and at the end of the 40 days storage, free asparaginase lost all of its activity, while immobilized asparaginase still showed 30% activity. Operational stability of immobilized asparaginase was tested for 8 successive usage, and immobilized asparaginase lost only 15% of its initial activity. In present study, activities of free and immobilized L-asparaginase were tested in artificial human serum medium, to foresee the in vivo efficiency, and it was demonstrated here that immobilized L-asparaginase protected its 74.74% of its initial activity in artificial serum medium.

Controlled release of curcumin from poly(HEMA-MAPA) membrane.

In this work, poly(HEMA-MAPA) membranes were prepared by UV-polymerization technique. These membranes were characterized by SEM, FTIR, and swelling studies. Synthesized membranes had high porous structure. These membranes were used for controlled release of curcumin which is already used as folk remedy and used as drug for some certain diseases and cancers. Curcumin release was investigated for various pHs and temperatures. Optimum drug release yield was found to be as 70% at pH 7.4 and 37 °C within 2 h period. Time-depended release of curcumin was also investigated and its slow release from the membrane demonstrated within 48 h.