Objective      To synthesize a novel chitosan-nanoparticles-fluorescein isothiocyanate fluorescent nanoprobe (CS-NP-FITC)

and to explore its physical properties

targeting ability and cytotoxicity.       Methods      CS-NP-FITC was synthesized by ionic cross-linking. A Zetasizer Nano ZS instrument was used to measure the diameter and zeta potential of CS-NP-FITC. The morphology of CS-NP-FITC was examined using a scanning electron microscope. CS-NP-FITC was labeled by aptamer S58 targeting transforming growth factor-β receptorⅡ (TβRⅡ) to test the targeting ability to specific receptors in human Tenon’s capsule fibroblasts. At last

the cytotoxicity of CS-NP-FITC was studied by LDH cytotoxicity assay.       Results      The mean diameter of CS-NP-FITC was 274.6 nm

and the zeta potential of CS-NP-FITC was +24.3 mV. The spherical particles were uniformly distributed shown by the scanning electron microscopy. CS-NP-FITC labeled by aptamer S58 could specifically bind to TβRⅡ under a laser scanning confocal microscope. LDH cytotoxicity assay showed that CS-NP-FITC at concentration between 0.18 mg/mL to 18 mg/mL had low cytotoxicity and fine biocompatibility.       Conclusion      Our study reveal that CS-NP-FITC labeled by suitable aptamer or antibody can specificly bind to target receptors. Due to its low cytotoxicity

CS-NP-FITC has the potential to be applied in bio-imaging.