Bovine serum albumin-capped gold nanoclusters conjugating with methylene blue for efficient 1O2 generation via energy transfer

Bovine serum albumin (BSA)-capped gold nanoclusters (BSA-Au NCs) are attractive photosensitizers for efficient singlet oxygen O-1(2) generation owing to their high-water solubility, low toxicity, and the broad absorption from UV to visible wavelengths, and the long lifetime of the electronic excitations (of the order of microseconds). However, the O-1(2) generation efficiency of BSA-Au NCs is relatively low. In the present study, a conjugate of BSA-Au NCs and methylene blue (MB) (BSA-Au NC-MB conjugate) has been developed to improve O-1(2) generation for antimicrobial photodynamic therapy (aPDT). The BSA-Au NC-MB conjugate demonstrated enhanced O-1(2) generation compared to the case of BSA-Au NCs and effective aPDT ability under white-light LED illumination for only 1 min due to the resonance energy transfer from the Au NCs to the MB in the conjugate. To the best of my knowledge, this is first report of Au NCs on the resonance energy transfer application for efficient O-1(2) generation. Therefore, the BSA-Au NC-MB conjugate is a novel photosensitizer for O-1(2) generation that shows great potential for aPDT, and the present study also develops a Very simple strategy to fabricate albumin-based nanoparticles for PDT. (C) 2017 Elsevier Inc. All rights reserved.