Unlabeled fluorescence ELISA using yellow emission carbon dots for the detection of Alicyclobacillus acidoterrestris in apple juice

Abstract

Juice spoilage caused by Alicyclobacillus acidoterrestris has troubled the global manufacturers for many years. Most approaches have failed to detect this bacterium with desirable sensitivity and selectivity because of their inherent drawbacks. In this work, carbon dots (CDs) with bright fluorescence were prepared which can be quenched by the HRP-catalyzed oxidation product of p-phenylenediamine, via inner filter effect. Therefore, an unlabeled fluorescence ELISA strategy incorporating CDs as signal reporter was developed for the detection of A. acidoterrestris in apple juice. This approach showed excellent performance on target identification with enhanced specificity, achieving a limit of detection of 3.2 × 102 CFU/mL. It is expected that this method could provide a reliable way for timely identification of A. acidoterrestris, effectively warning against the emergence of juice spoilage incidence.