One-pot synthesis of gold nanoclusters with bright red fluorescence and good biorecognition Abilities for visualization fluorescence enhancement detection of E. coli

• A facile one-pot strategy was developed for the synthesis of lysozyme functionalized fluorescence gold nanoclusters.
• The lysozyme functionalized fluorescence gold nanoclusters demonstrate good biorecognition abilities.
• This nanosensor can be used for fluorescence enhancement detection of E. coli.

A facile one-pot strategy was developed for the synthesis of lysozyme functionalized fluorescence gold nanoclusters (AuNCs). The lysozymes added to reduce Au3+ ions and stabilize the AuNCs during the synthesis were coated on the AuNCs surface and retained their specific recognition ability for bacteria such as Escherichia coli (E. coli). Based on such ability, these AuNCs were specifically attached onto the surface of E. coli, which resulted in great red fluorescence enhancement. Nevertheless, the bovine serum albumin (BSA) stabilized AuNCs could not recognize E. coli and no fluorescence enhancement was observed. Upon the addition of E. coli, the red fluorescence intensity of lysozyme-AuNCs was enhanced linearly over the range of 2.4×104 −6.0×106 CFU/mL of E. coli with high sensitivity (LOD=2.0×104 CFU/mL, S/N=3). The visualization fluorescence evolution may enable the rapid and real-time detection of bacteria. This study may be extended to other functional proteins such as antibody, enzyme, and peptide functionalized nanoclusters while retaining the bioactivity of coating proteins and find wide applications in the fields of biochemistry and biomedicine.

Lysozyme functionalized fluorescence gold nanoclusters with good biorecognition ability were synthesized through a facile one-pot strategy and utilized for the fluorescence enhancement detection of E. coli.Figure optionsDownload as PowerPoint slide