New Colorimetric DNA Sensor for Detection of Campylobacter jejuni in Milk Sample Based on Peroxidase-Like Activity of Gold/Platinium Nanocluster

A new colorimetric DNA sensor for trace Campylobacter jejuni DNA genome in food samples was investigated. 30 mer DNA probe-based on hipo gene of Campylobacter jejuni and 12 cytosine nucleotide in tail without any chemical modification was used as the sensing element. 12 cytosine nucleotide utilized as a scaffold for stabilization of Au/Pt nanoclusters. Peroxidase like activity of Au/Pt nanocluster probe with the addition of bacterial target DNA and hybridization process decreased. The experiment showed that step by step increase in bacterial target DNA gradually decreased peroxidase activity, which was linear. Limit of detection for this bacterial DNA sensor was 20 pM and superiority of this DNA sensor for detection of Campylobacter jejuni DNA in comparison with other target DNA was significant. The method was successfully applied to the analysis of bacterial target DNA in milk samples, with results similar to those obtained by the PCR methodology as comparative method.