The
precise monitoring of H2S has aroused immense research
interest in the biological and biomedical fields since it is exposed
as a third endogenous gasotransmitter. Hence, there is an urgent requisite
to explore an ultrasensitive and economical H2S detection
system. Herein, we report a simple strategy to configure an extremely
sensitive electrochemical sensor with a 2D nanosheet-shaped layered
double hydroxide (LDH) wrapped carbon nanotubes (CNTs) nanohybrid
(CNTs@LDH), where a series of CNTs@CuMn-LDH nanohybrids with varied
amounts of LDH nanosheets grafted on a conductive CNTs backbone has
been synthesized via a facile coprecipitation approach. Taking advantage
of the unique core–shell structure, the integrated electrochemically
active CuMn-LDH nanosheets on the conductive CNTs scaffold, the maximum
interfacial collaboration, and the superior specific surface area
with a plethora of surface active sites and ultrathin LDH layers,
the as-prepared CNTs@CuMn-LDH nanoarchitectures have exhibited superb
electrocatalytic activity toward H2S oxidation. Under the
optimum conditions, the electrochemical sensor based on the CNTs@CuMn-LDH
nanohybrid shows remarkable sensing performances for H2S determination in terms of a wide linear range and a low detection
limit of 0.3 nM (S/N = 3), high selectivity, reproducibility, and
durability. With marvelous efficiency achieved, the proposed sensing
platform has been practically used in in situ detection
of abiotic H2S efflux produced by sulfate reducing bacteria
and real-time in vitro tracking of H2S
concentrations from live cells after being excreted by a stimulator
which in turn might serve as early diseases diagnosis. Thus, our core–shell
hybrid nanoarchitectures fabricated via structural integration strategy
will open new horizons in material synthesis, biosensing systems,
and clinical chemistry.