Hemolysis-Inspired, Highly Sensitive, Label-Free IgM Detection Using Erythrocyte Membrane-Functionalized Nanomechanical Resonators

Abstract

Immunoglobulin detection is important for immunoassays, such as diagnosing infectious diseases, evaluating immune status, and determining neutralizing antibody concentrations. However, since most immunoassays rely on labeling methods, there are limitations on determining the limit of detection (LOD) of biosensors. In addition, although the antigen must be immobilized via complex chemical treatment, it is difficult to precisely control the immobilization concentration. This reduces the reproducibility of the biosensor. In this study, we propose a label-free method for antibody detection using microcantilever-based nanomechanical resonators functionalized with erythrocyte membrane (EM). This label-free method focuses on the phenomenon of antibody binding to oligosaccharides (blood type antigen) on the surface of the erythrocyte. We established a method for extracting the EM from erythrocytes and fabricated an EM-functionalized microcantilever (MC), termed EMMC, by surface-coating EM layers on the MC. When the EMMC was treated with immunoglobulin M (IgM), the bioassay was successfully performed in the linear range from 2.2 pM to 22 nM, and the LOD was 2.0 pM. The EMMC also exhibited excellent selectivity compared to other biomolecules such as serum albumin, γ-globulin, and IgM with different paratopes. These results demonstrate that EMMC-based nanotechnology may be utilized in criminal investigations to identify blood types with minimal amounts of blood or to evaluate individual immunity through virus-neutralizing antibody detection.

Potential effects of probiotics (immunobacteryne; IMB) on growth performance, feed efficacy, blood biochemical, redox balance, nonspecific immunity and heat‐shock protein expression of Nile tilapia (Oreochromis niloticus) fingerlings

“…Our research findings concluded that there was a significant increase in phagocyte and lysozyme activities in the group fed diet containing 1.5 g IMB/kg diet, which could be a result of increased release from the lysosomes or the proliferating phagocytes. Additionally, IgM is the first antibody the body makes when it fights a new infection (Lee et al, 2022). Also, IgM plays several crucial roles in maintaining B cell survival and lymphoid tissue architecture, which was increased significantly in the 1 and 1.5 g IMB/kg diet‐fed groups (Michaud et al, 2020).…”