| dc.description.abstract | Electrochemical approaches to myriad medical and environmental challenges are highly
attractive due to their strong potential for extensive and green applications. Point of care
diagnostics through the electrochemical monitoring of clinically and environmentally relevant
molecules are gaining attraction due to their low cost and simple fabrication procedures. The
development of highly stable and sensitive electrochemical sensors/biosensors, for a wide variety
of biomolecules in actual samples, makes these methods alternative analytical tools in different
pharmaceutical and hospital laboratories. Electrochemical biocatalysis is an additional promising
area to address the removal of bacteria for the generation of safe potable water. As the world’s
population is dealing with lack of access to safe drinking water, photoelectrocatalysis has been
investigated as a very efficient technique for the destruction of pathogenic bacteria in water.
Nanomaterials with dimensions of less than 100 nm have great potential to enhance the
performance of electrochemical methods, due to their excellent electronic, mechanical, and
thermal properties. These materials have the capacity to greatly enhance biocatalytic activity, and
thus greatly improve the performance of electrochemical sensors/biosensors. This remarkable
improvement in bacterial catalysis has been studied using a novel synergistic approach, which
incorporates both photocatalysts and electrocatalysts.
For my PhD thesis, we designed a high-performance electrochemical sensor based on
graphene for the sensitive detection of acetaminophen, valacyclovir, and mixtures thereof. This
sensor was fabricated through the concurrent electrochemical reduction and deposition of
graphene oxide (GO) onto a glassy carbon electrode (GCE) using cyclic voltammetry (CV). The
electrocatalytic properties of the electrochemically reduced graphene (ERG) for the oxidation of
acetaminophen were analyzed via cyclic voltammetry (CV), differential pulse voltammetry,
(DPV) and chronoamperometry. For comparison, various ERG/GCEs were prepared under
different electrodeposition cycles to optimize the required quantity of ERG. Our experimental
results indicated that the optimized ERG/GCE possessed robust activity toward the
electrochemical oxidation of acetaminophen, valacyclovir, and their mixture, leading to the
development of a highly sensitive electrochemical sensor for its detection. An extremely low
detection limit of 2.13 nM for acetaminophen, and 1.34 nM for the exclusive detection of
valacyclovir was achieved. A wide linear detection range of from 5.0 nM to 800 μM was achieved via the combination of an amperometric technique and DPV. The developed
electrochemical sensor was further employed for the determination of acetaminophen,
valacyclovir, and their mixture in human serum, with excellent recovery, ranging from 96.08%
to103.2%. The fabricated electrochemical sensor also demonstrated high selectivity, stability and
reproducibility. | en_US |
