Single laboratory method validation for antibody conjugated silica nanoparticles for rapid detection of Campylobacter jejuni

This research was to perform single laboratory method validation for antibody conjugated silica nanoparticles (FDS-NPs) for the rapid detection of Campylobacter jejuni in chicken samples. The FDS-NPs have a round shape with an average size of 10-100 nm. Some aggregates were detected. FT-Raman spectrum revealed that FDS-NPs surface was modified with carboxyl functional group and allowed them to bind with monoclonal antibodies against C. jejuni. The antibody-conjugated FDS-NPs attached to bacteria cell and could be identified clearly under epifluorescent microscope. The cells were extremely bright orange with rounded surface and moved directionless under microscope. FDS-NPs were used to detect C. jejuni in chicken samples from a slaughterhouse (100 carcass rinsed, 100 cloacal swab and 100 viscera content) according to ISO16140 guidance. Values of relative accuracy, specificity, and sensitivity for FDS-NPs were 85.0, 82.5 and 90.0%, respectively. The Kappa value of test of inter-agreement was acceptable, compared with standard method. FDS-NPs technique was equivalent to conventional but gave much faster results (30 min compared with 5 days).