Ultrasensitive detection of disease biomarkers using an immuno-wall device with enzymatic amplification

Abstract

We present a fluorometric sandwich immunoassay for biomarkers utilizing an antibody-modified microfabricated wall and antibody labeled with an enzyme for signal amplification.

Rapid, Sensitive, and Selective Detection of H5 Hemagglutinin from Avian Influenza Virus Using an Immunowall Device

“…Our previous research has suggested that DDAO molecules could be accumulated inside the wall and could efficiently magnify the fluorescence intensity. 32 First, a standard solution of H5-HA in PBS (20 ng/mL) was used as a model to probe the fluorescence intensity variation during 30 min. It was found that the fluorescence intensity considerably increased as a function of time (Figure 4a), and the value of the signal/blank ratio (S/B) because of the DDAO accumulation inside the immunowall was slightly improved.…”

“…To improve the sensitivity, an enzyme label was used, and the signal was amplified by the enzymatic reaction with a fluorogenic substrate. 32…”

“…We previously reported a microdevice for immunoassay using a three-dimensional photopolymer structure (immunowall) fabricated in a microchannel, called the immunowall device. The immunowall device provides a fast, easy, and highly sensitive detection of disease biomarkers. − In the immunowall device, a biotinylated capture antibody is immobilized on the wall structure surface through biotin–streptavidin (SA) interaction. Introducing an analyte and secondary and labeled antibodies produces a sandwich complex anchored on the sides of the wall.…”

Recent Advances in Microfluidic Technology for Bioanalysis and Diagnostics

“…Besides portability, sensitivity of the method is important to detect low-concentrated biomarkers. Tokeshi and co-workers presented very sensitive immunoassays for disease biomarkers, where the capture antibodies are immobilized at the channel walls to improve the limit of the detection …”

“…Tokeshi and co-workers presented very sensitive immunoassays for disease biomarkers, where the capture antibodies are immobilized at the channel walls to improve the limit of the detection. 176 Extracellular Vesicles (EV). Exosomes secreted by cells are considered as valuable biomarkers to diagnose various diseases, such as cancer, as well as potential drug delivery vehicles.…”