Bovine serum albumin (BSA) was used to conjugate with the
AuNRs based on the method described by Moustafa et al. [51]. The
BSA was dissolved in the phosphate-buffered saline (PBS: 150 mM
NaCl, 1.9 mM NaH2PO4, 8.1 mM Na2HPO4, pH of 7.4) at a concentration
of 0.25 mM.1mL of the 0.25mMBSAwas added to 10 mL of
the AuNR solution (0.3 nM) and stirred vigorously for 8 h at room
temperature. Afterwards, the reaction was stopped by removing
the excess BSA by centrifugation at 10,000 rpm for 5 min and the
precipitate was re-suspended in ultrapure water.