Fig 4. AuNP TPPL intensities measured at various depths from the surface of cell spheroids after 72 hour incubation.

a) four different AuNSs, b) four different AuNS-oligos functionalized with 28 base long oligonucleotides and c) four different AuNRs, Note that the controls and low intensity measurements can be slightly negative due to background subtraction (details in Methods).