Soares Raquel R A, Hjort Robert G, Pola Cicero C, Parate Kshama, Reis Efraim L, Soares Nilda F F, McLamore Eric S, Claussen Jonathan C, Gomes Carmen L
Department of Mechanical Engineering, Iowa State University, Ames 50011, Iowa, United States.
Department of Food Technology, Federal University of Viçosa, Viçosa 36570-900, Brazil.
ACS Sens. 2020 Jul 24;5(7):1900-1911. doi: 10.1021/acssensors.9b02345. Epub 2020 Apr 29.
Food-borne illnesses are a growing concern for the food industry and consumers, with millions of cases reported every year. Consequently, there is a critical need to develop rapid, sensitive, and inexpensive techniques for pathogen detection in order to mitigate this problem. However, current pathogen detection strategies mainly include time-consuming laboratory methods and highly trained personnel. Electrochemical in-field biosensors offer a rapid, low-cost alternative to laboratory techniques, but the electrodes used in these biosensors require expensive nanomaterials to increase their sensitivity, such as noble metals (e.g., platinum, gold) or carbon nanomaterials (e.g., carbon nanotubes, or graphene). Herein, we report the fabrication of a highly sensitive and label-free laser-induced graphene (LIG) electrode that is subsequently functionalized with antibodies to electrochemically quantify the food-borne pathogen serovar Typhimurium. The LIG electrodes were produced by laser induction on the polyimide film in ambient conditions and, hence, circumvent the need for high-temperature, vacuum environment, and metal seed catalysts commonly associated with graphene-based electrodes fabricated via chemical vapor deposition processes. After functionalization with antibodies, the LIG biosensors were able to detect live in chicken broth across a wide linear range (25 to 10 CFU mL) and with a low detection limit (13 ± 7 CFU mL; = 3, mean ± standard deviation). These results were acquired with an average response time of 22 min without the need for sample preconcentration or redox labeling techniques. Moreover, these LIG immunosensors displayed high selectivity as demonstrated by nonsignificant response to other bacteria strains. These results demonstrate how LIG-based electrodes can be used for electrochemical immunosensing in general and, more specifically, could be used as a viable option for rapid and low-cost pathogen detection in food processing facilities before contaminated foods reach the consumer.
食源性疾病日益引起食品行业和消费者的关注，每年报告的病例数以百万计。因此，迫切需要开发快速、灵敏且廉价的病原体检测技术，以缓解这一问题。然而，目前的病原体检测策略主要包括耗时的实验室方法和需要高度训练的人员。电化学现场生物传感器为实验室技术提供了一种快速、低成本的替代方案，但这些生物传感器中使用的电极需要昂贵的纳米材料来提高其灵敏度，例如贵金属（如铂、金）或碳纳米材料（如碳纳米管或石墨烯）。在此，我们报告了一种高灵敏度、无标记的激光诱导石墨烯（LIG）电极的制备，该电极随后用抗体进行功能化，以电化学方式定量食源性病原体鼠伤寒血清型。LIG电极是在环境条件下通过激光诱导在聚酰亚胺薄膜上制备的，因此无需高温、真空环境以及通常与通过化学气相沉积工艺制备的基于石墨烯的电极相关的金属种子催化剂。在用抗体进行功能化后，LIG生物传感器能够在宽线性范围内（25至10 CFU/mL）检测鸡汤中的活菌，检测限低（13±7 CFU/mL；n = 3，平均值±标准差）。这些结果是在平均响应时间为22分钟的情况下获得的，无需样品预浓缩或氧化还原标记技术。此外，这些LIG免疫传感器表现出高选择性，对其他细菌菌株无明显响应。这些结果表明，基于LIG的电极一般可用于电化学免疫传感，更具体地说，可作为食品加工设施中在受污染食品到达消费者之前进行快速、低成本病原体检测的可行选择。
