Electrochemical immune-biosensor for immunoglobulin G based bioelectrocatalytic reaction on micro-comb electrodes

Abstract

A new amplification strategy of electrochemical signaling from antigen-antibody interactions was proposed via back-filling immobilization of horseradish peroxidase (HRP), immunoglobulin G antibodies (anti-IgG) and gold nanoparticles onto a three-dimensional sol-gel (3DSG)-functionalized biorecognition interface. The 3DSG sol-gel network was employed not only as a building block for the surface modification but also as a matrix for ligand functionalization. The signal-amplification was based on the bioelectrocatalytic reaction of the back-filling immobilization of HRP to H(2)O(2). With the non-competitive format, the formation of the antigen-antibody complex by a simple one-step immunoreaction between the immobilized anti-IgG and IgG in sample solution inhibited partly the active center of HRP, and decreased the immobilized HRP towards H(2)O(2) reduction. Under optimal conditions, the proposed immunosensor exhibited a good electrochemical behavior to IgG in a dynamic range of 1.12-162 ng/mL with a detection limit of 0.56 ng/mL (at 3delta). Moreover, the precision, reproducibility and stability of the as-prepared immunosensor were acceptable. Importantly, the proposed methodology would be valuable for diagnosis and monitoring of biomarkers and its metastasis.

Biosensors for Detecting Lymphocytes and Immunoglobulins

“…The enzyme HRP was used to block nonspecific bindings between antibodies and antigens. This immunosensor was tested in human serum and had a linear range of 1.12-162 ng/mL with a limit of detection (LOD) of 0.56 ng [34].…”

A new atomic absorption spectral assay for the determination of trace IgG using immunonanogold

“…Nanogold has novel optical and electric properties and good biocompatibility [15,16], it has been used in the light and electron microscopic observations in immunohistochemical researches and immunogold-labeled analysis [17,18]. Recently, the immunonanogold analytical techniques include electrochemical method [19][20][21], resonance scattering spectral assay [22][23][24], spectrophotometry [25], luminescence method [26,27], mass spectrometry [28,29]. However, there is no report about AAS used to study nanogold-labeled immunoreaction for IgG.…”