Abstract:
Inability of antibiotics repertoire to effectively control the
progress of multi-drug resistant (MDR) bacteria has prompted
the substantial curiosity among the scientists to seek new
tactics to combat the bacterial growth. Therefore, to eradicate
the pathogenic bacteria with least cytotoxicity, we employed
carbon dots as a broad spectrum of antibacterial weapons in
the presence of visible light. Instead of using citric acid, we
engaged the penicillin G as a carbon source for the synthesis of
penicillin carbon dots (PCDs), which made the carbon dots
more aggressive towards pathogenic microbes. Penicillin was
also covalently attached to –NH2 containing citric acid based
CDs (CDs-Penicillin) via an amide bond to evaluate whether
penicillin in the form of PCD has retained its activity or in its
conjugated form (CDs-Penicillin). Synthesized dots were assessed for their antibacterial activity against Staphylococcus
aureus, Escherichia coli (DH5a), MDR Escherichia coli and
Methicillin-resistant Staphylococcus aureus in the presence as
well as the absence of visible light. The mechanism of bacteriakilling through cell wall rupturing was investigated using
scanning electron microscopy. Antibacterial assay demonstrates
that penicillin in the form of PCDs retained its activity and
possess great prospects in the development of new bactericidal
therapies to invade the MDR bacteria. Cytotoxicity of both
PCDs and CDs-Penicillin has been evaluated by measuring the
viability of human HeLa cells. Fluorescence images of bacteria
collected using different excitation wavelength.
