  A significantly large scope is available for the scientific and engineering
developments of high-throughput ultra-high sensitive oxygen sensors. We give a
perspective of oxygen sensing for two physical states of matters - solid-state
nanomaterials and plasma. From single-molecule experiments to material
selection, we reviewed various aspects of sensing, such as capacitance,
photophysics, electron mobility, response time, and a yearly progress. Towards
miniaturisation, we have highlighted the benefit of lab-on-chip-based devices
and showed exemplary measurements of fast real-time oxygen sensing. From the
physical-chemistry perspective, plasma holds a strong potential in the
application of oxygen sensing. We investigated the current state-of-the-art of
electron density, temperature, and design issues of plasma systems. We also
show a numerical aspects of low-cost approach towards developing plasma-based
oxygen sensor from household candle flame. In this perspective, we give an
opinion about a diverse range of scientific insight together, identifies the
short comings, and opens the path for new physical-chemistry device
developments of oxygen sensor along with providing a guideline for innovators
in oxygen sensing.
