title: Ultra-small particles of iron oxide as peroxidase for immunohistochemical detection.
abstract: Dimercaptosuccinic acid (DMSA) modified ultra-small particles of iron oxide (USPIO) were synthesized through a two-step process. The first step: oleic acid (OA) capped Fe(3)O(4) (OA-USPIO) were synthesized by a novel oxidation coprecipitation method in H(2)O/DMSO mixing system, where DMSO acts as an oxidant simultaneously. The second step: OA was replaced by DMSA to obtain water-soluble nanoparticles. The as-synthesized nanoparticles were characterized by TEM, FTIR, TGA, VSM, DLS, EDS and UV-vis. Hydrodynamic sizes and Peroxidase-like catalytic activity of the nanoparticles were investigated. The hydrodynamic sizes of the nanoparticles (around 24.4 nm) were well suited to developing stable nanoprobes for bio-detection. The kinetic studies were performed to quantitatively evaluate the catalytic ability of the peroxidase-like nanoparticles. The calculated kinetic parameters indicated that the DMSA-USPIO possesses high catalytic activity. Based on the high activity, immunohistochemical experiments were established: using low-cost nanoparticles as the enzyme instead of expensive HRP, Nimotuzumab was conjugated onto the surface of the nanoparticles to construct a kind of ultra-small nanoprobe which was employed to detect epidermal growth factor receptor (EGFR) over-expressed on the membrane of esophageal cancer cell. The proper sizes of the probes and the result of membranous immunohistochemical staining suggest that the probes can be served as a useful diagnostic reagent for bio-detection.
authors: Jiangsu Key Laboratory for Biomaterials and Devices, State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, People's Republic of China.
authors: Yihang
authors: Y
authors: Wu
authors: Mengjie
authors: M
authors: Song
authors: Zhuang
authors: Z
authors: Xin
authors: Xiaoqing
authors: X
authors: Zhang
authors: Yu
authors: Y
authors: Zhang
authors: Chunyu
authors: C
authors: Wang
authors: Suyi
authors: S
authors: Li
authors: Ning
authors: N
authors: Gu
mesh_terms: D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000378:metabolism; D004938:Esophageal Neoplasms / Q000175:diagnosis; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D009195:Peroxidase / Q000378:metabolism*; D004113:Succimer / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide; D004113:Succimer; D009195:Peroxidase; D066246:ErbB Receptors