The peptide (Ac-CILPWKWPWWPWRR-CONH2) was synthesized using an automatic synthesizer (Syro I MultiSynThec, Wullener, Germany), as previously reported.33 (link) The peptide was characterized using reversed-phase high-performance liquid chromatography (Shimadzu Corporation, Kyoto, Japan), on a column equipped with an ultraviolet Lambda-Max Model 481 detector, and liquid chromatography–mass spectrometry (Finnigan/Thermo Electron Corporation, San Jose, CA, USA).
Purified peptide was conjugated, in the presence of 10 mmol/L citrate buffer (pH 6), to Au-NPs (Cod. 752.568; Sigma-Aldrich, St Louis, MO, USA) with a diameter of 5 nm (5.47×1013 NPs/mL), as previously reported.34 (link) The functionalized NPs were purified by centrifugation (14,000 g for 30 min) and the pellet was resuspended in PBS in the presence of 0.05% (v/v) Triton X-100. To calculate the amount of peptide coupled to AuNPs, fluorimetric measurements were carried out using a Varian Carry Eclipse spectrometer (Agilent Technologies, Santa Clara, CA, USA). The fluorimetric and zeta potential (ZP) measurements have been previously reported.35 (link) The final peptide concentration coupled to AuNPs was 250 µM.
Purified peptide was conjugated, in the presence of 10 mmol/L citrate buffer (pH 6), to Au-NPs (Cod. 752.568; Sigma-Aldrich, St Louis, MO, USA) with a diameter of 5 nm (5.47×1013 NPs/mL), as previously reported.34 (link) The functionalized NPs were purified by centrifugation (14,000 g for 30 min) and the pellet was resuspended in PBS in the presence of 0.05% (v/v) Triton X-100. To calculate the amount of peptide coupled to AuNPs, fluorimetric measurements were carried out using a Varian Carry Eclipse spectrometer (Agilent Technologies, Santa Clara, CA, USA). The fluorimetric and zeta potential (ZP) measurements have been previously reported.35 (link) The final peptide concentration coupled to AuNPs was 250 µM.
