Fig. 2
From: DNA-enabled rational design of fluorescence-Raman bimodal nanoprobes for cancer imaging and therapy

Raman reporter selection. a Fabrication of FRNPs. (i) A bifunctional amine-thiol modified DNA is labeled with a NIR fluorophore via straightforward NHS ester chemistry. (ii) Thiol-ends of the fluorophore-labeled DNAs are grafted on to the AuNP surface to create a fluorophore shell. (iii) NPs are silicated using a modified Stöber method. b Representative TEM image of the FRNPs. c The UV–vis absorption spectra of the 4 different fluorophores selected. d The representative baseline-subtracted Raman spectra of 100 fM of the FRNPs synthesized using the 4 fluorophores