TABLE II.

XPS determined compositions of NH₂-SAMs on 24 nm AuNPs after undergoing a C11 NH₂-thiol ligand-exchange with a C2 NH₂-SAM for 21 days followed by purification (before adding HCl), purification then adding 24 drops of HCl solution (with HCl), or purification then adding 24 drops of HCl solution and rinsing (after rinsing HCl). Data for the sample with the unrinsed acid treatment was renormalized without the Cl signals.

	at. % (std. dev.)
21 days ligand-exchanged	C1s	Au4f	N1s	O1s	S2p
Before adding HCl	51.6(1.2)	36.4(0.9)	4.7(0.4)	3.5(0.6)	3.6(0.4)
With HCl	51.5(1.2)	39.7(1.1)	4.8(0.3)	1.3(0.1)	2.8(0.2)
After rinsing HCl	54.8(1.4)	36.0(2.0)	4.8(0.4)	1.4(0.6)	2.7(0.2)