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Successful applications of mesoporous materials often require different surface properties of internal pore walls and external surfaces. The different functional moieties on the different surfaces enable them to fulfill multiple application demands. In this study, we introduce a nanostopper approach to selectively functionalize the different surfaces of porous silicon (PSi). The external surface was functionalized with amine groups to further graft with folic acid (FA) and fluorescein isothiocyanate (FITC) for targeting and imaging, respectively. The pore walls were functionalized with carboxyl groups to obtain a higher loading degree of doxorubicin and realize a pH-triggered drug release. The engineered PSi drug carrier showed specific targeting against cancer cells and improved cell internalization due to the FA functionalization. Moreover, the PSi carrier presented an intracellular drug delivery with pH-triggered functionality. With the selective modification, the loading degree of the drug was increas...

Atomic layer deposition (ALD) was used to deposit thin films of molybdenum nitride from a new precursor, bis(tert-butylimido)-bis(dimethylamido)molybdenum, and ammonia. The optimum ALD growth window was 260−300 °C and the maximum growth per cycle 0.5 A. Deposition temperatures are lower than with the previously reported molybdenum pentachloride as the precursor. Molybdenum nitride was successfully deposited on silicon, electrochemically grown nickel, chromium, and quartz glass. Growth per cycle was maintained over substrate materials of different types. Conformality of the deposited films was as high as 98%. Films were mainly amorphous, containing small amounts of the β-Mo2N phase. According to time-of-flight elastic recoil detection analysis (TOF-ERDA), the molybdenum−nitrogen ratio was close one. Together with X-ray diffraction data this suggests the existence of a nitrogen-rich amorphous phase in the film.