Nanoscope iiia scanning probe microscope

The thickness of ca. 10 nanobelts was measured for each sample by atomic force microscopy (AFM). A multimode Nanoscope IIIa scanning probe microscope (Digital Instruments) mounted with Si tips with tip radius less than 10 nm and force constant at ca. 40 N/m was operated in a tapping mode. The resonant frequency and scanning rate were set at ca. 300 kHz and 1 Hz respectively. AFM specimen was the same as that used for TEM experiments, i.e. droplets of Ag nanobelts suspended in ethanol were dried on the carbon-coated copper grid.

Particle size, polydispersity index (PDI), and zeta potential of CaCO₃, CaCO₃/Rapa, and CD9-Lac/CaCO₃/Rapa were analyzed using a Zetasizer Nano ZS (Malvern Instruments, Malvern, UK) equipped with Nano DTS software (version 6.34). Morphological analyses of CaCO₃/Rapa and CD9-Lac/CaCO₃/Rapa were carried out using TEM and AFM. TEM (H7600, Hitachi, Tokyo, Japan) analysis of carbon-coated copper grid loaded with CaCO₃/Rapa or CD9-LAC/CaCO₃/Rapa dispersion was conducted using 2% phosphotungstic acid solution as negative stain. Similarly, CaCO₃/Rapa or CD9-LAC/CaCO₃/Rapa deposited on ultraflat mica square plates (Ted Pella, Inc., USA) were used for AFM analysis with a Nanoscope^® IIIa Scanning Probe Microscope (Digital Instruments, USA). Furthermore, FTIR analyses of dried Lac-PEG-COOH conjugate and CD9-Lac/CaCO₃/Rapa were carried out using a Thermo Scientific Nicolet Nexus 670 FTIR spectrophotometer.