The dextrin coated AuNPs (∼12.5 nm in diameter) synthesized using the alkaline procedure were functionalized with a thiolated probe (TB 3 thiol) following a common methodology applicable for citrate coated AuNPs ligand exchange (Anderson et al., 2010; Hill and Mirkin, 2006).
Briefly, the thiolated DNA probe (5 nmol) was reduced with DTT and purified using a Sephadex column (Nap-5,
GE Healthcare).