Synthesis of nitrogen-doped carbon nanodots to destroy bacteria competing with Campylobacter jejuni in enrichment medium, and development of a monoclonal antibody to detect C. jejuni after enrichment

Abstract

The objective of this study was to develop a method with improved sensitivity for Campylobacter jejuni detection in foods. Nitrogen-doped carbon nanodots (N-CNDs) were synthesized and added to an enrichment medium (Bolton broth) at a concentration of 10 mg/mL. A light-emitting diode (LED) at a wavelength of 425 nm was used to irradiate the N-CNDs-supplemented enrichment medium to induce an exothermic reaction for 1 h. Additionally, a monoclonal antibody specific to C. jejuni NCTC11168 was developed using hybridoma cells to aid detection. The C. jejuni detection capabilities of N-CNDs-supplemented enrichment medium and the conventional Bolton broth enrichment, were compared using duck samples. C. jejuni in the enrichment was detected with the monoclonal antibody based-indirect enzyme-linked immunosorbent assay (ID-ELISA). The N-CNDs-supplemented enrichment medium showed a better C. jejuni detection capability than the conventional Bolton broth enrichment. Additionally, data from ID-ELISA showed excellent detection efficiency and a shortened detection time in the N-CNDs-supplemented enrichment medium after LED irradiation at 425 nm. These results indicate that 1-h LED irradiation at 425 nm to Bolton broth supplemented with the N-CNDs increased the detection efficiency and shortened the detection time with the monoclonal antibody for C. jejuni in food.