# Polymer-Stabilized Silver (Gold)-Zinc Oxide Nanoheterodimer Structures as Antimicrobials
## 3 Results
SAED patterns demonstrate concentric rings with intermittent dots, indicating that these nanoparticles are crystalline in nature. Table 1 contains the XRD characteristics of the composites. The crystal structures of metal-containing components in the obtained noble metal-zinc oxide heterostructures stabilized by a copolymer were studied by powder XRD (Table 1, Figure S2). The X-ray examination of heterodimer samples showed the presence of the following crystalline phases: the cubic phase related to either silver or gold and the hexagonal phase of zinctite (ZnO) with the average sizes of 6-9 and 16-20 nm (Table 1), respectively. The mean crystallite sizes of the nanoparticles were calculated from the broadening of the peaks using the Scherrer formula (Supplementary Materials). The peaks corresponding to the Ag crystal phase are at \(\sim\)38.1 and 44.2\({}^{\circ}\); those corresponding to the Au crystal phase are at \(\sim\)38.2 and 44.3\({}^{\circ}\); those corresponding to the ZnO (zinctite) phase are at \(\sim\)31.8, 34.4, 36.1, 47.5, and 56.7. Their positions correspond to the Miller indexes: 111 and 002 for Ag(Au), and 100, 002, 101, 102, and 110 for ZnO (Figure S2). The content of AgNPs in the crystalline phase of the corresponding samples VM/Ag\({}^{0}\)/ZnO, EM/Ag\({}^{0}\)/ZnO, and SM/Ag\({}^{0}\)/ZnO was 80-91% and zinc oxide was 8-20%. The gold-containing composite VM/Au\({}^{0}\)/ZnO contained 77.5% AuNPs and 22.5% zinctite. The chemical compositions of the samples VM/Ag\({}^{0}\)/ZnO and VM/Au\({}^{0}\)/ZnO were studied by XPS. The Au 4f\({}_{7/2}\), Zn 2p\({}_{3/2}\) a, and Zn 3p spectra are given in Figures 3 and 4. In view of the overlap of the photoelectron spectra of Zn 3p and Au 4f core levels in the spectrum of the VM/Au\({}^{0}\)/ZnO composite and the presence of a satellite peak characteristic of the Zn 3p spectrum, the analysis of the spectra was started from the Zn 3p core-level of Ag\({}^{0}\)/ZnO nanoheterodimer stabilized with VM. The spectrum is presented as a sum of two Gaussian peaks at 89.4 and 92.25 eV, which are related to 3p\({}_{3/2}\) and 3p\({}_{1/2}\) sublevels with the 3p\({}_{3/2}\)/3p\({}_{1/2}\) branching ratio of 0.5 and the satellite peak at 86.39 eV (subtracted for clarity). The latter describes a low-energy region and may be assigned to a specific energy loss [93; 94; 95]. The corresponding characteristics of the photoelectron spectrum given in Table S1 were used for approximation of the Zn 3p-Au 4f energy region of the VM/Au\({}^{0}\)/ZnO sample. For better perception, the satellite peaks associated with the energy losses of photoelectrons have been subtracted in Figure 3. The spectrum of Zn 3p core-level spectrum of the VM stabilized Au\({}^{0}\)/ZnO nanoheterodimer was approximated with two spin-orbit doublets and with the same constraints. The Zn 2p\({}_{3/2}\) XPS spectra of VM/Ag\({}^{0}\)/ZnO and VM/Au\({}^{0}\)/ZnO samples (Figure 4) are close each other and may be presented as a sum of two Gaussian profiles at 1022.19 and 1024.20 eV, and 1022.20 and 1023.83 eV, respectively, with the same Gaussian width of 1.44 eV. As for the Au 4f spectrum, it was approximated with two 4f\({}_{7/2}\)-4f\({}_{5/2}\) spin-orbit doublets with spin-orbit splitting of 3.65 eV and branching ratio of 1.33. The binding energies of 83.88 and 84.80 eV are attributed to the Au\({}^{0}\) and Au\({}^{+}\) states related to Au-Zn-O and Au-O-Zn structures, respectively [96; 97; 98]. Table S1 presents the characteristics of the Zn 3p and Au 4f spectra. The Ag 3d XPS spectrum (Figure 5) is characterized with two main symmetric Ag 3d\({}_{5/2}\) and Ag 3d\({}_{3/2}\) peaks at 368.14 and 374.14 eV and two satellite peaks shifted relative to the main peaks by 3.4 eV. The latter are descriptors of Ag\({}^{0}\) state. A negative CLS by 0.13 eV relative to the reference value of 368.27 eV may be attributed to Ag-Zn bonds [96]. The binding energies of 367.6 and 373.6 eV recorded for Ag-doped ZnO were assigned to Ag 3d\({}_{5/2}\) and Ag 3d\({}_{3/2}\) core levels and attributed to Ag-O bonds [93].