Conjugation of Carboxylated Graphene Quantum Dots with Cecropin P1 for Bacterial Biosensing Applications

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 E. coli, using a biosensing procedure that focuses on measuring changes in fluorescence quenching. Our CGQDs were conjugated with cecropin P1, a naturally-produced antibacterial peptide that facilitates the attachment of CGQDs to E. coli 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).