Nitric oxide (NO) exhibits a crucial role in various
versatile
and distinct physiological functions. Hence, its real-time sensing
is highly important. Herein, we developed an integrated nanoelectronic
system comprising a cobalt single-atom nanozyme (Co-SAE) chip array
sensor and an electronic signal processing module (INDCo‑SAE) for both in vitro and in vivo multichannel qualifying of NO in normal and tumor-bearing mice.
The high atomic utilization and catalytic activity of Co-SAE endowed
an ultrawide linear range for NO varying from 36 to 4.1 × 105 nM with a low detection limit of 12 nM. Combining in situ attenuated total reflectance surface enhanced infrared
spectroscopy (ATR-SEIRAS) measurements and density function calculation
revealed the activating mechanism of Co-SAE toward NO. The NO adsorption
on an active Co atom forms *NO, followed by the reaction between *NO
and OH–, which could help design relevant nanozymes.
Further, we investigated the NO-producing behaviors of various organs
of both normal and tumor-bearing mice using the proposed device. We
also evaluated the NO yield produced by the wounded mouse using the
designed device and found it to be approximately 15 times that of
the normal mouse. This study bridges the technical gap between a biosensor
and an integrated system for molecular analysis in vitro and in vivo. The as-fabricated integrated wireless
nanoelectronic system with multiple test channels significantly improved
the detection efficiency, which can be widely used in designing other
portable sensing devices with multiplexed analysis capability.