A novel sensitive electrochemical immunoassay with colloidal gold as the antibody labeling tag and subsequent signal amplification by silver enhancement is described. Colloidal gold was treated by a light-sensitive si...A novel sensitive electrochemical immunoassay with colloidal gold as the antibody labeling tag and subsequent signal amplification by silver enhancement is described. Colloidal gold was treated by a light-sensitive silver enhancement system which made silver deposit on the surface of colloidal gold(form Au/Ag core-shell structure), followed by the release of the metallic silver atoms anchored on the antibody by oxidative dissolution of them in an acidic solution and the indirect determination of the dissolved Ag + ions by anodic stripping voltammetry(ASV) at a carbon fiber microelectrode. The electrochemical signal is directly proportional to the amount of analyte(goat IgG) in the standard or a sample. The method was evaluated by means of a noncompetitive heterogeneous immunoassay of immunoglobulin G(IgG) with a concentration as low as 0.2 ng/mL. The high performance of the method is related to the sensitive ASV determination of silver(Ⅰ) at a carbon fiber microelectrode and to the release of a large number of Ag + ions from each silver shell anchored on the analyte(goat IgG).展开更多
A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengi- neering (LIBB), Chinese Academy of Sciences (CAS). The system was designed to deliver a defined numbers of hydro- ge...A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengi- neering (LIBB), Chinese Academy of Sciences (CAS). The system was designed to deliver a defined numbers of hydro- gen ions, produced by a van de Graaff accelerator, in an en- ergy range of 2.0—3.0 MeV, into an area smaller than that of the nucleus of an individual living cell. The beam is colli- mated by a borosilicate glass capillary that forms the beam-line exit. An integrated computer program recognizes the cells and locates them one by one over the microbeam exit for irradiation. We present technical details of the CAS-LIBB microbeam facility, particularly on the collimator, hardware, control program, as well as cell irradiation proto- cols available. Various factors contributing to the targeting and positioning precision are discussed along with accuracy measurement results.展开更多
基金Supportted by the National Natural Science Foundation of China( No.2 0 0 730 16 ,6 0 2 710 2 0 ),86 3projects( No.2 0 0 2 AA302203)and973projects( No.G19990 6 4 5 0 4 )
文摘A novel sensitive electrochemical immunoassay with colloidal gold as the antibody labeling tag and subsequent signal amplification by silver enhancement is described. Colloidal gold was treated by a light-sensitive silver enhancement system which made silver deposit on the surface of colloidal gold(form Au/Ag core-shell structure), followed by the release of the metallic silver atoms anchored on the antibody by oxidative dissolution of them in an acidic solution and the indirect determination of the dissolved Ag + ions by anodic stripping voltammetry(ASV) at a carbon fiber microelectrode. The electrochemical signal is directly proportional to the amount of analyte(goat IgG) in the standard or a sample. The method was evaluated by means of a noncompetitive heterogeneous immunoassay of immunoglobulin G(IgG) with a concentration as low as 0.2 ng/mL. The high performance of the method is related to the sensitive ASV determination of silver(Ⅰ) at a carbon fiber microelectrode and to the release of a large number of Ag + ions from each silver shell anchored on the analyte(goat IgG).
文摘A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengi- neering (LIBB), Chinese Academy of Sciences (CAS). The system was designed to deliver a defined numbers of hydro- gen ions, produced by a van de Graaff accelerator, in an en- ergy range of 2.0—3.0 MeV, into an area smaller than that of the nucleus of an individual living cell. The beam is colli- mated by a borosilicate glass capillary that forms the beam-line exit. An integrated computer program recognizes the cells and locates them one by one over the microbeam exit for irradiation. We present technical details of the CAS-LIBB microbeam facility, particularly on the collimator, hardware, control program, as well as cell irradiation proto- cols available. Various factors contributing to the targeting and positioning precision are discussed along with accuracy measurement results.
