<p>Quantum
dots have proven to be strong candidates for biosensing applications in recent
years, due to their strong light emission properties and their ability to be
modified with a variety of functional groups for the detection of different
analytes. Here, we investigate the use
of conjugated carboxylated graphene quantum dots (CGQDs) for the detection of <i>E. coli</i>, using a biosensing procedure
that focuses on measuring changes in fluorescence quenching. We have also further developed this biosensing assay into a compact, field-deployable test kit focused on rapidly measuring changes in absorbance to determine bacterial concentration. Our CGQDs were conjugated with cecropin P1, a
naturally-produced antibacterial peptide that facilitates the attachment of CGQDs
to <i>E. coli</i> cells. We also confirm the structural modification
of these conjugated CGQDs in addition to analyzing their optical
characteristics. Our findings have the
potential to be used in situations where rapid, reliable detection of bacteria
in liquids, such as drinking water, is required, especially given our biosensor’s
relatively low observed limit of detection (LOD).</p><br>
Photocatalytic inactivation of
Escherichia coli
under UV light irradiation using large surface area anatase TiO
2
quantum dots