Aflatoxin B1 (AFB1) contamination has raised global concerns in agricultural and food industry; thus, sensitive, accurate and rapid AFB1 sensors are essential in many circumstances. Herein, we developed a label-free and immobilization-free ratiometric homogeneous electrochemical aptasensor based on hybridization chain reaction (HCR) for facile and rapid determination of AFB1. Methylene blue (MB) and ferrocene (Fc) were used as label-free probes to produce a response signal (I_MB) and a reference signal (I_Fc) in solution phase, respectively. The ratio of I_MB/I_Fc was used as a yardstick to quantify AFB1. HCR was exploited to enlarge the intensity of I_MB as well as ratiometric signal. By combining label-free homogeneous assay and ratiometric strategy, the resulting aptasensor offered sensitive, rapid, and reliable determinations of AFB1 with a detection limit of 38.8 pg mL^-1. The aptasensor was then used to determine AFB1 in cereal samples with comparable reliability as HPLC-MS.

黄曲霉毒素 B1 (AFB1) 污染引起了全球农业和食品行业的关注；因此，灵敏、准确和快速的 AFB1 传感器在许多情况下都是必不可少的。在此，我们开发了一种基于杂交链反应 (HCR) 的无标记和无固定化比例均质电化学适体传感器，可轻松快速地测定 AFB1。亚甲蓝 (MB) 和二茂铁 (Fc) 用作无标记探针，分别在溶液相中产生响应信号 (I _MB ) 和参考信号 (I _Fc )。I _MB /I _{Fc 的}比率用作量化 AFB1 的尺度。HCR 被用来扩大 I _MB的强度以及比率信号。通过结合无标记均相测定和比率策略，所得适体传感器提供了灵敏、快速和可靠的 AFB1 测定，检测限为 38.8 pg mL ^-1。然后使用适体传感器测定谷物样品中的 AFB1，其可靠性与 HPLC-MS 相当。