2.4 Synthesis of DOX@RCNs
200mg RCNs were dispersed into 50mL deionized water and treated with ultrasound for 20 min. After the ultrasonication, 40mg DOX was added to the above-mentioned dispersions stirred slowly overnight. Then, centrifugation was performed to eliminate the unadsorbed DOX. So far, DOX@RCNs were prepared. The drug loading rate was obtained by measuring the absorbance of the supernatant by UV-vis-NIR spectrophotometer. The adsorption capacity was calculated by the following formula: