Smartphone-based chemiluminescence detection of aflatoxin B via labelled and label-free dual sensing systems

To develop a sensing platform for onsite determination of AFB in foodstuffs, we developed smartphone-based chemiluminescence detection of AFB via labelled and label-free dual modes. The labelled mode was characteristic of double streptavidin-biotin mediated signal amplification, obtaining limit of detection (LOD) of 0.04 ng/mL in the linear range of 1-100 ng/mL. To reduce the complexity in the labelled system, a label-free mode based on both split aptamer and split DNAzyme was fabricated. A satisfactory LOD of 0.33 ng/mL was generated in the linear range of 1-100 ng/mL. Both labelled and label-free sensing systems achieved outstanding recovery rate in AFB-spiked maize and peanut kernel samples. Finally, two systems were successfully integrated into smartphone-based portable device based on custom-made components and android application, achieving comparable AFB detection ability to a commercial microplate reader. Our systems hold huge potential for AFB onsite detection in food supply chain.