A novel chemiluminescence immunoassay of staphylococcal enterotoxin B using HRP-functionalised mesoporous silica nanoparticle as label

A novel chemiluminescence immunoassay was developed, in which two monoclonal antibodies recognised different epitopes of staphylococcal enterotoxin B (SEB) using HRP-functionalised mesoporous silica nanoparticle (MSN) as label. The enzyme-functionalised MSN was fabricated by co-immobilizing HRP and anti-SEB onto the surface of MSN simultaneously using glutaraldehyde as the linkage. Because the large surface area of MSN carriers increased the amount of HRP and the proportion between the enzyme and antibody molecules on the surface of MSN were optimised, the conjugates provided a much higher signal. This is an improvement over the traditional sandwich immunoassay which often has one or two enzyme molecules per antibody. The analysis showed a linear response within the range of 0.01-1 ng mL(-1) (r = 0.9967), and the detection limit (DL) was 4 pg mL(-1) (3 sigma). This approach was successfully demonstrated as a simple, cost-effective, sensitive method to detect SEB in milk, water and serum samples. (C) 2012 Elsevier Ltd. All rights reserved.