Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Positive TOF-SIMS spectra of (a) bare, (b) positively charged and (c) negatively charged SPIONs; negative TOF-SIMS spectra of (d) bare, (e) positively charged and (f) negatively charged SPIONs after incubation with the biofilm. The intensity of each peak was different for each sample. The intensity peak ratios changed from one sample to the others.
