Dual-color AgNCs-enabled fluorescent aptasensor for the simultaneous detection of KAN and AFB1

Kanamycin (KAN) and aflatoxin B1 (AFB1) are often misused by illegal breeders. Improper storage of livestock feed can lead to contamination and residue, posing serious risks to human health and the environment. In this study, we developed a dual-color fluorescent aptasensor for the simultaneous detection of KAN and AFB1. The sensor utilized DNA-templated silver nanoclusters (AgNCs) with two distinct emission colors as the fluorescent probe and guanine-rich (G-rich) sequences as capture probes. In the presence of KAN or AFB1, the respective targets selectively bound to their corresponding aptamer fragments, forming an aptamer-target-aptamer complex, leading to amplified fluorescence of the AgNCs induced by the G-rich sequences and base pairing. This "turn-on" dual-color fluorescent aptasensor method demonstrated excellent detection performance, achieving detection limits of 0.86 nM for KAN and 0.71 nM for AFB1, and highlighted the reliability and potential of the aptasensor for multiplexed detection of antibiotics and toxins in feed samples.