Hoang Chau Nguyen Minh, Nguyen Son Hai, Tran Mai Thi
VinUni-Illinois Smart Health Center, VinUniversity, Hanoi, Vietnam.
School of Mechanical Engineering, Hanoi University of Science and Technology, Hanoi, Vietnam.
Sci Rep. 2025 Aug 12;15(1):29548. doi: 10.1038/s41598-025-14189-4.
Escherichia coli represents a significant concern for food safety, water quality, medical applications, and environmental health, necessitating effective detection methods. This study presents a reduced graphene oxide-based biosensor for the sensitive and specific detection of E. coli DNA. The functionalized reduced graphene oxide was successfully synthesized using a modified Hummers' method, followed by a hydrothermal reduction step. Structural, morphological, and chemical properties of the reduced graphene oxide were confirmed through Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The biosensor incorporates functionalized reduced graphene oxide linked to amino-modified probe DNA sequences specific to E. coli markers, providing stability and selective hybridization. Detection of E. coli DNA in the range of 0-476.19 fM is achieved by measuring absorbance changes at 273 nm, where an increase in absorbance indicates the presence of complementary E. coli single-stranded DNA. Performance testing with various DNA concentrations revealed a linear relationship, achieving a limit of detection of 80.28 fM and demonstrating high selectivity against non-target bacteria such as Bacillus subtilis, Enterococcus, Vibrio proteolyticus, and Staphylococcus. Optimization efforts identified the amino-E.coli BL21 probe as the only probe capable of detecting E. coli DNA. The reduced graphene oxide-based biosensor holds promise for rapid detection in pathogen monitoring, clinical diagnostics, and environmental analysis, paving the way for enhanced DNA biosensing technologies.
大肠杆菌对食品安全、水质、医学应用和环境卫生构成重大威胁，因此需要有效的检测方法。本研究提出了一种基于还原氧化石墨烯的生物传感器，用于灵敏且特异的大肠杆菌DNA检测。采用改进的Hummers法成功合成了功能化还原氧化石墨烯，随后进行水热还原步骤。通过傅里叶变换红外光谱、扫描电子显微镜和X射线衍射对还原氧化石墨烯的结构、形态和化学性质进行了确认。该生物传感器包含与大肠杆菌标记物特异的氨基修饰探针DNA序列相连的功能化还原氧化石墨烯，提供稳定性和选择性杂交。通过测量273 nm处的吸光度变化实现了0 - 476.19 fM范围内大肠杆菌DNA的检测，吸光度增加表明存在互补的大肠杆菌单链DNA。对不同DNA浓度进行的性能测试显示出线性关系，检测限达到80.28 fM，并对枯草芽孢杆菌、肠球菌、溶蛋白弧菌和葡萄球菌等非靶标细菌表现出高选择性。优化工作确定氨基 - 大肠杆菌BL21探针是唯一能够检测大肠杆菌DNA的探针。基于还原氧化石墨烯的生物传感器在病原体监测、临床诊断和环境分析中的快速检测方面具有潜力，为增强DNA生物传感技术铺平了道路。
