Recent foodborne outbreaks in multiple locations necessitate the continuous development of highly sensitive and specific biosensors that offer rapid detection of foodborne biological hazards. This work focuses on the development of a reduced graphene oxide‑titanium dioxide (rGO-TiO₂) nanocomposite based aptasensor to detect Salmonella enterica serovar Typhimurium. A label-free aptamer was immobilized on a rGO-TiO₂ nanocomposite matrix through electrostatic interactions. The changes in electrical conductivity on the electrode surface were evaluated using electroanalytical methods. DNA aptamer adsorbed on the rGO-TiO₂ surface bound to the bacterial cells at the electrode interface causing a physical barrier inhibiting the electron transfer. This interaction decreased the DPV signal of the electrode proportional to decreasing concentrations of the bacterial cells. The optimized aptasensor exhibited high sensitivity with a wide detection range (10⁸ to 10¹ cfu mL⁻¹), a low detection limit of 10¹ cfu mL⁻¹ and good selectivity for Salmonella bacteria. This rGO-TiO₂ aptasensor is an excellent biosensing platform that offers a reliable, rapid and sensitive alternative for foodborne pathogen detection.

最近在多个地点发生的食源性疾病暴发，需要不断开发高度灵敏和特异的生物传感器，以提供对食源性生物危害的快速检测。这项工作的重点是基于氧化石墨烯-二氧化钛（rGO-TiO ₂）纳米复合材料的适体传感器的开发，该传感器可检测肠炎沙门氏菌血清型鼠伤寒沙门氏菌。通过静电相互作用将无标记的适体固定在rGO-TiO ₂纳米复合材料基质上。使用电分析方法评估电极表面上的电导率变化。吸附在rGO-TiO ₂上的DNA适体在电极界面处与细菌细胞结合的表面会形成物理屏障，从而抑制电子转移。这种相互作用使电极的DPV信号降低，与细菌细胞浓度的降低成正比。优化的适体传感器显示出高灵敏度，检测范围广（10 ⁸至10 ¹  cfu mL ^-1），低检测限10 ¹  cfu mL ^-1，对沙门氏菌具有良好的选择性。这款rGO -TiO ₂适体传感器是出色的生物传感平台，可为食源性病原体检测提供可靠，快速和灵敏的替代方案。