IgE detection in allergic patient's serum by absorption analysis of biofunctionalised microparticles

Abstract

Allergic diseases have increased its incidence worldwide, increasing the significance of research in diagnostics to offer more precise immunotherapy options. Most current lines of work revolve around single-protein detection, which relies mostly on faint fluorescence signals and large expensive detectors. In this context, we propose a procedure based on visible light absorption by polymeric microparticles. The beads acting as supports react with the serum of an allergic patient and perform a magnetically-assisted immunoassay, similar to indirect ELISA. Firstly, protein binding on surface and antibody recognition was evaluated by SEM imaging. Then, the procedure sensibility was determined, were the lowest detected IgE concentration is 24 ng/mL, and the response is linear within a working range comparable to commercial standards. Finally, the effects of cross-reactive allergen specimens were assessed, yielding difficulties in detection at antibody concentrations below 36 ng/mL. Consequently, we have provided a proof-of-concept of a microparticle-based immunoassay with affordable miniaturization capability for benchtop equipement.

Bimodal determination of immunoglobulin E by fluorometry and ICP-MS by using platinum nanoclusters as a label in an immunoassay

“…Such LOD is lower than the LOD of 0.2 ng mL -1 for IgE with fluorescent detection using an immunoprobe labelled with AuNCs [30]. Also, it compares favorably with most recently published methods for IgE determination in human serum (see Table 2) [30][31][32][33][34][35][36][37][38]. With ICP-MS detection of platinum, the linear range (IC20-IC80) extended from 0.10 ng mL -1 up to 2.6 ng mL -1 of IgE.…”

Immunoglobulin E Detection Method Based on Cascade Enzymatic Reaction Utilizing Portable Personal Glucose Meter

“…A strong linear relationship (R 2 = 0.9796) existed in the range of 10-400 ng/mL, and the limit of detection (LOD) (3σ/slope) was ca. 29.59 ng/mL, which is comparable to or higher than the limits of other human IgE assay methods (Table 1) [37][38][39][40][41][42][43][44][45][46][47]. Notably, the detection sensitivity of our strategy was sufficient to detect clinically important human IgE concentrations in human serum (>240 ng/mL) [48].…”