Table 1.

Summary of the obtained XPS data BE (binding energy), FWHM (full width at half maximum), and the assignment from the enlisted references of ${\mathrm{Au}}^{\mathrm{III}}{\mathrm{Cl}}_4^{-}$, ${\mathrm{Pt}}^{\mathrm{II}}{\left({\mathrm{NH}}_3\right)}_4^{2+}$, Au⁰ solid, Pt⁰ solid, polyethylene glycol (PEG)-2NH₂, Au-PEG NPs (nanoparticles), and Au:Pt-PEG NPs.

Compound	Atomic Core Level	BE (eV)	FWHM (eV)	Assignment
${\mathrm{Au}}^{\mathrm{III}}{\mathrm{Cl}}_4^{-}$ *	Au-4f7/2	87.8	1.3	AuIII
	Au-4f5/2	91.5	1.3	AuIII
${\mathrm{Pt}}^{\mathrm{II}}{\left({\mathrm{NH}}_3\right)}_4^{2+}$	Pt-4f7/2	73.0	1.7	PtII
	Pt-4f5/2	76.3	1.7	PtII
	N-1s	400.2	1.6	Pt-NH3+
Au0 solid	Au-4f7/2	84.1	0.9	Au0
	Au-4f5/2	87.8	0.9	Au0
Pt0 solid	Pt-4f7/2	71.1	1.2	Pt0
	Pt-4f5/2	74.5	1.2	Pt0
PEG-2NH2	C-1s	285.9	1.3	C–O and C–N
	O-1s	532.4	1.4	C–O–H
				C–O–C
	N-1s	398.8	1.4	C–N
	N-1s	399.8	1.4	C-NH2
Au-PEG NPs	Au-4f7/2	82.9	0.8	Au0
	Au-4f5/2	86.6	0.8	Au0
	C-1s	285.9	1.2	C–O and C–N
	C-1s	284.4	1.0	C–C
	O-1s	532.2	1.3	C–O–H
				C–O–C
	N-1s	399.0	1.9	C-NH2
				Au-NH2
	N-1s	400.9	1.6	---NH2
Au:Pt-PEG NPs	Au-4f7/2	82.8	1.0	Au0
	Au-4f5/2	86.5	1.0	Au0
	Pt-4f7/2 surf.	70.2	1.9	Pt0
	Pt-4f5/2 surf.	73.5	1.9	Pt0
	Pt-4f7/2 core	72.1	1.8	Pt–N
	Pt-4f5/2 core	75.4	1.8	Pt–N
	C-1s	285.9	1.2	C–H and C–N
	C-1s	284.3	0.9	C–C
	O-1s	532.2	1.3	C–O–C
	N-1s	399.1	2.1	C-NH2
				Au:Pt-NH2
	N-1s	401.0	1.5	---NH2/NH3+

* the HAuCl₄ compound was reduced under XPS analysis (Au4f^7/2 at 85.3 eV assigned to Au^I).