Facile Solvothermal Preparation of MnCuO Microspheres: Excellent Electrocatalyst for Real-Time Detection of HO Released from Live Cells.

Hydrogen peroxide (HO) is an eminent biomarker in pathogenesis; a selective, highly sensitive real-time detection of HO released from live cells has drawn a significant research interest in bioanalytical chemistry. Binary transition-metal oxides (BTMOs) displayed a recognizable benefit in enhancing the sensitivity of HO detection; although the reported BTMO-based HO sensor's detection limit is still insufficient, it is not appropriate for in situ profiling of trace amounts of cellular HO. In this paper, we describe an efficient, reliable electrochemical biosensor based on MnCuO (MCO) microspheres to assay cellular HO. The MnCuO microspheres were prepared through a superficial solvothermal method. It is obvious from impedance studies, introduction of manganese into copper oxide lattice significantly improved the ionic conductivity, which is beneficial for the electrochemical sensing process. Thanks to the distinct microsphere structure and excellent synergy, MCO-modified electrode exhibited excellent nonenzymatic electrochemical behavior toward HO sensing. The MCO-modified electrode delivered a broad working range (36 nM to 9.3 mM) and an appreciable detection limit (13 nM), with high selectivity toward HO. To prove its practicality, the developed sensor was applied in the detection of cellular HO released by RAW 264.7 cells in presence of CHAPS. These results label the possible appliance of the sensor in clinical analysis and pathophysiology. Thus, BTMOs are evolving as a promising candidate in designing catalytic matrices for biosensor applications.