Thesis title: Electrochemical biosensors for food quality markers detection
The aim of this PhD is to design and rigorously evaluate electrochemical biosensors
as practical tools for monitoring food safety and quality. Conventional lab techniques—
mass spectrometry (MS), gas chromatography (GC), and high-performance liquid
chromatography (HPLC)—remain the gold standard for contaminant analysis, but
they’re often slow, costly, and often requires a specialized staff and dedicated facilities.
These constraints pointed out the need for faster, affordable, and decentralized testing,
especially for complex food matrices.
In this context, electrochemical biosensors address this need allowing the
development of low cost, and miniaturized electrochemical sensors exploiting the
sensitivity and selectivity of biological recognition elements with two complementary
routes. The first one exploits the catalytic power and the efficient electron transfer of
the multi-heme enzyme cytochrome c nitrite reductase (ccNiR), which supports direct
electron transfer (DET) and which was integrated into a nanostructured screen-printed
electrode to create a sensitive, selective sensor for nitrite in cured meats. The second
route employs antibodies for their high selectivity toward small toxic molecules,
targeting contaminants such as pesticides and mycotoxins.
Because antibody orientation, stability and activity critically affect sensor performance,
the work places strong emphasis on its immobilization onto the electrode surface. Two
different strategies have been developed by involving (i) functionalized magnetic
nanoparticles (PEI-MNPs) which long chains allows for antibody loading and
orientation, and (ii) electrodeposited gold on 3D-printed conductive electrodes
combined with self-assembled monolayers (SAMs) to enable robust covalent coupling.
Together, these approaches improved conductivity, reproducibility, and the integration
of low-cost, adaptable transducers into biosensing platforms.
Overall, the thesis has a dual focus: advancing fundamental understanding of enzyme
electrode and antibody–electrode interfaces and translating this knowledge into the
development of reliable electrochemical devices tailored to the requirements of food
safety monitoring. The central argument is that careful choices of biorecognition
elements, electrode material, and immobilization strategy can help move biosensors
from academic prototypes to deployable tools for the agri-food sector.