Switching-peptides for one-step immunoassay and its application to the diagnosis of human hepatitis B

One-Step Homogeneous Immunoassay for the Detection of Influenza Virus Using Switching Peptide and Graphene Quencher

“…Homogeneous immunoassay indicated that antigen–antibody interactions occurred in solution without immobilization of antibodies. One-step homogeneous immunoassays can be conducted in solution by simply mixing the sample and reagent solutions [ 1 ]. As the antibodies show fluorescence after binding to fluorescence-labeled switching peptides, a quencher molecule was bound to the detection antibodies to absorb the fluorescence from the switching peptides before the binding of the antigens (target analytes).…”

“…The switching peptides were derived from the self-assembly regions of immunoglobulin G (IgG), which are the frame regions (FRs) at the antigen-binding pockets, as shown in Fig. 1 a [ 1 ]. As the FRs have a conserved amino acid sequence in IgG for different antigens and different source animals, the switching peptides could be generally used for nearly all kinds of IgGs [ 2 – 5 ].…”

“…As shown in Fig. 1 b, such switching peptides can be effectively used for one-step immunoassays without the need for washing [ 1 , 6 – 9 ]. When the antigen binds to the corresponding region of the antigen-binding site of IgG, the switching peptides labeled with fluorescence get dissociated from IgG.…”

Carbon electrode obtained via pyrolysis of plasma-deposited parylene-C for electrochemical immunoassays

“…Thermal deposition was performed using a conventional parylene deposition system obtained from Kisco (Osaka, Japan). [4][5][6][7][8] Deposition was conducted in three steps: (1) evaporation of the parylene-C dimer at 160 °C, (2) decomposition of the parylene-C precursor to reactive free radicals (monomers) at 650 °C, and (3) polymerization of the free radicals at ambient temperature. The entire process was performed under a vacuum of 5.3 Pa (40 mTorr), and the film thickness was controlled by the initial amount of parylene-C dimer used.…”

“…[1][2][3] Various types of parylene dimers, with different functional groups attached to their benzene rings, are used, such as parylene-C bearing a chloride, parylene A bearing a primary amine, and parylene H bearing a formyl group. [4][5][6] Because deposition is conducted in the gas phase, the deposited parylene film exhibits a highly homogeneous thickness, even if the substrate exhibits a very complicated 3D structure. 7,8 Parylene-C, in particular, is widely used in various applications due to its physi-cal and chemical properties, such as transparency and high electric isolation and resistances to organic solvents.…”