Preparation Of Gold Nanoparticles Bioprobe And Its Application In Biomedicine

In recent years, spherical gold nanoparticles (GNPs) and gold nanorods (GNRs) have gained increasing interest owing to their unique physical and chemical properties, such as excellent optical property in localized surface plasmon resonance (LSPR), good biocompatibility, easy and efficient surface modification. Many applications in various fields in biosensing, drug delivery and site-specific diagnostic and therapy in cancer have been developed.Herein, water-soluble GNRs were synthesized via a well-established seed-mediated method, using the cationic surfactant cetyltrimethylammonium bromide (CTAB) as a capping agent. To employ as a carrier for drug delivery, the surfaces of GNRs were modified with thioled poly(ethylene glycol) SH-PEG and negatively charged polyelectrolyte polyacrylic acid (PAA) to get the stable GNRs probes in different solutions with negative charged surfaces. Then positively charged anti-cancer drug, doxorubicin, was loaded onto the surfaces of GNRs via electrostatic attraction. Drug-loaded PEG-PAA-GNRs probes was carried out for the treatment of prostate cancer DU145 cells, demonstrating that the GNRs probes can serves as a promising carrier for drug delivery. In addition, we developed a novel one-pot method to fabricate monodispersed GNPs by reducing HAuCl4 with galactosamine. The method was easy to operate and the size of GNRs can be simply controlled by changing the pH of solution. Furthermore, the as-prepared GNPs were successfully utilized as a novel bioprobe for the rapid and sensitive detection of ricin agglutinin RCA120 with the detection limit of 2 ng/mL. The characterization method used here are transmission electron microscopy (TEM), fluorescence spectrophotometer, fluorescence microscopy, UV-Vis spectrophotometer, and etc.