Cronobacter sakazakii (C. sakazakii) can cause extremely high mortality diseases especially in infants, so it is necessary to rapidly and specifically detect C. sakazakii in powdered infant formula (PIF). In this work, the amplification strategy of methylene blue (MB)-anchored graphene oxide (GO) was used to develop an electrochemical aptasensor for detecting C. sakazakii easily and quickly. In the absence of C. sakazakii, GO would be bound to the aptamer of C. sakazakii by π-π interaction, and then adsorbed MB through electrostatic adherence; thus, the electrochemical signal of MB amplified. While in the presence of C. sakazakii, the bacteria would be specifically combined with the aptamer, and hindered the electrostatic adsorption of GO and MB to the aptamer, resulting in the decreasing electrochemical signal of MB. The fabricated electrochemical aptasensor showed a wide linear range from 2 × 10¹ to 2 × 10⁶ CFU mL⁻¹ of the bacteria concentration, and its limit of detection reached 7 CFU mL⁻¹ (S/N = 3). In addition, the applicability of the aptasensor in PIF for the analysis of C. sakazakii was successfully demonstrated. This aptasensor would provide a new method for the detection of C. sakazakii but also a novel sensing platform for the rapid detection of pathogen bacteria.

阪崎肠杆菌（C. sakazakii）会引起极高的死亡率，尤其是在婴儿中，因此必须快速，特异性地检测婴儿配方奶粉（PIF）中的阪崎肠杆菌。在这项工作中，使用亚甲基蓝（MB）锚定的氧化石墨烯（GO）的扩增策略开发了一种电化学适体传感器，可轻松快速地检测出阪崎肠杆菌。在缺少阪崎肠杆菌的情况下，GO会通过π - π相互作用与阪崎肠杆菌的适体结合，然后通过静电粘附吸附MB。因此，MB的电化学信号被放大。在阪崎肠杆菌的存在下，细菌会与适体特异性结合，阻碍GO和MB静电吸附到适体上，导致MB的电化学信号降低。所制备的电化学适体传感器显示出细菌浓度从2×10 ¹到2×10 ⁶  CFU mL ^-1的宽线性范围，其检出限达到7 CFU mL ^-1（S / N  = 3）。另外，成功地证明了PIF中的适体传感器对阪崎肠杆菌的分析的适用性。该适体传感器将为检测阪崎肠杆菌提供一种新方法，而且为快速检测病原菌提供了一种新颖的传感平台。