Facile solvothermal synthesis of ultrathin spinel ZnMn2O4 nanospheres: An efficient electrocatalyst for in vivo and in vitro real time monitoring of H2O2.

[Display omitted] • The ultrathin ZnMn 2 O 4 (ZMO) nanospheres were prepared by facile solvothermal method. • The ZMO exhibited wide linearity (20 nM-10 mM) with low detection limit (8.3 nM). • The developed biosensor showed rapid response (> 3s), high selectivity and stability. • The proposed sensor was applied for in-vivo and in-vitro real-time analysis of H 2 O 2.. Hydrogen peroxide (H 2 O 2) is a renowned industrial oxidant that plays a significant role in cell biology, and pathogenesis. On this note, we propose a simple Zinc Manganese Oxide (ZnMn 2 O 4 ; ZMO) based H 2 O 2 sensor for rapid in-situ tracking and determination of H 2 O 2 from live cells, and bio-samples. The ZMO catalyst have been synthesized via simple scalable protocol; surface morphology, elemental composition, electronic states, crystallinity, and other physiochemical properties are studied and discussed in-detail using various spectroscopic tools. The ZMO modified electrode displays an excellent electrochemical activity toward H 2 O 2 sensing with a wide dynamic range (20 nM-10 mM), low detection limit (8.3 nM), excellent selectivity, reproducibility, operational stability, and rapid response time (<3 s). Further, the ZMO modified electrode have been found successful at in-vivo real-time tracking of H 2 O 2 released from live HeLa cells, and in-vitro analysis of H 2 O 2 spiked in water, tooth paste, and human serum samples. [ABSTRACT FROM AUTHOR]