Rhizopus stolonifer produces large
postharvest losses that account for about 80% of total losses in prepackaged
and loose tomato fruits from Rhizopus rot. In this study, we effectively synthesized a Cu- and Sn-codoped
mesoporous BaTiO3–G–SiO2 (CuSnBTGS)
nanocomposite by utilizing a simple, low-cost self-assembly method
for the electrochemical detection of Rhizopus stolonifer fungus; this method does not require a biological or chemical receptor
or antibodies. We focused on the microstructure design of CuSnBTGS
in combination with Cu and Sn codoping, which is widely regarded as
the most efficient way to produce high-performance electrodes. The
resultant CuSnBTGS composite exhibited excellent electrochemical characteristics
and remarkable performance in the direct detection of Rhizopus stolonifer (bread fungus) levels in contaminated
solutions. The chronoamperometric response of the CuSnBTGS composite
electrode was linear with Rhizopus stolonifer fungus concentrations in the 50–100 μL range, with
a lower detection limit of 0.50 μL. The sensor electrode demonstrated
high sensitivity, repeatability, and selectivity. The findings show
that Cu- and Sn-codoped mesoporous BTGS is a viable alternative to
costly electrode materials, such as gold and platinum, for amperometric
sensor applications, demonstrating its applicability in the agricultural
and food safety sectors.