Catalase immobilized antimonene quantum dots used as an electrochemical biosensor for quantitative determination of H2O2 from CA-125 diagnosed ovarian cancer samples.

A selective and cost-effective biosensor based on catalase immobilized antimonene quantum dots modified glassy carbon electrode (Cat@AMQDs-GCE) is designed for the first time to determine hydrogen peroxide (H2O2). Antimonene quantum dots (AMQDs) are synthesized by a single step method, characterized by various analytical techniques and applied to the electrochemical sensing of hydrogen peroxide. Catalase enzyme specific for H2O2 reduction is immobilized onto AMQDs to facilitate its detection by cyclic voltammetry and amperometry. Concentration, scan rate, pH, stability and selectivity are optimized. Linearity of Cat@AMQDs-GCE is determined as 0.989 with limit of detection as 4.4 μM. Amperometric measurements show recovery of 95 to 103.4% for H2O2 from human serum samples. Cat@AMQDs-GCE is electrochemically stable up to 30 cycles, reducing the cost of analysis. Cat@AMQDs-GCE shows good selectivity in presence of ascorbic acid, dopamine, leucine and glucose. Prepared electrode is also applied for the quantitative determination of H2O2 from ovarian cancer serum. CA 125 concentration is previously determined by Elecsys CA 125 II Assay. Results demonstrate that concentration of H2O2 increases with increasing levels of CA125 in serum.