A paper-based nanogold dot blot assay for the detection of Campylobacter spp.

Campylobacter is one of the leading causes of bacterial foodborne disease worldwide and is considered to be responsible for over 280,000 cases of food poisoning in the UK each year. The development of effective methods that do not require polymerase chain reaction (PCR), as well as being suitable for point-of-care or on-site use is a major challenge. This would provide appropriate measures to identify infected animals or foods, reducing the risk of outbreaks and improving human health, as well as minimising economic loss. The aim of the study was to develop a dot blot assay using gold nanoparticles (AuNPs) and silver enhancement for the detection of Campylobacter spp. spiked in artificial and real samples. A variety of hybridisation buffers were used to optimise assay performance. The use of silver enhancement step increased the sensitivity of this detection method by 100 fold in comparison with the sole use of AuNPs as labels. The results indicate that PerfectHyb™ Plus hybridization buffer worked most efficiently, enabling a limit of detection (LOD) of 0.1 nM. The chicken rinse had a LOD of 1.33 nM, suggesting a real sample does not significantly affect the functionality of the assay. The assay is easy and quick to conduct and exhibits good specificity, proving its feasibility for practical application.