Fig. 4From: Silica diatom shells tailored with Au nanoparticles enable sensitive analysis of molecules for biological, safety and environment applicationsRaman spectra of pure BSA, BSA adsorbed by silicon dioxide shells, and BSA adsorbed by D24 systems, in the latter two experiments, the initial concentration of BSA was 10−16 (a). Optical microscopy inspection of D24 systems after incubation with BSA (b); Raman map of BSA acquired over individual D24 systems (c, d)Back to article page