Department of Pharmacy, Changzhi Medical College, Shanxi 046012, China.
Department of Pharmacy, Changzhi Medical College, Shanxi 046012, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Dec 15;303:123191. doi: 10.1016/j.saa.2023.123191. Epub 2023 Jul 24.
Food-borne pathogens in dairy products that was contaminated from raw ingredients or improper food handling can cause a major threaten to human health. Here, to construct the pathogens detection, a dual-signal readout fluorescent switching sensor was designed for one-step determination of Staphylococcus aureus (S. aureus), which was a marker of food contamination. Graphene oxide (GO) was used as a fluorescence quencher, while fluorophore-labeled hairpin DNA was used as a donor, resulting in fluorescence resonance energy transfer (FRET) from the fluorophore to GO (signal off). Enzyme-free hybridization chain reaction could generate remarkable signal amplification, which avoided the nonspecific desorption caused by any enzymatic proteins in GO surface. With the strong binding ability of aptamer to S. aureus, a long bifluorescent molecules-labeled double-stranded DNA product was formed, bringing in dual-signal readout responses (signal on). Consequently, a reliable, sensitive and selective sensor was obtained for one-step quantification of S. aureus concentration from 10 to 10 CFU/mL with a detection limit of 1 CFU/mL. Furthermore, satisfactory stability, reproducibility, specificity and good recovery efficiency in milk samples revealed that the proposed sensor could be served as a prospective tool for food safety analysis.
乳制品中的食源性致病菌，如果是由原材料污染或不当的食品处理造成的，可能会对人类健康造成重大威胁。在这里，为了构建病原体检测方法，设计了一种双信号读出荧光切换传感器，用于一步法测定金黄色葡萄球菌（S. aureus），金黄色葡萄球菌是食品污染的标志物。氧化石墨烯（GO）被用作荧光猝灭剂，而荧光标记的发夹 DNA 被用作供体，导致荧光从荧光团到 GO 的共振能量转移（FRET）（信号关闭）。无酶杂交链式反应可以产生显著的信号放大，从而避免了 GO 表面任何酶蛋白引起的非特异性解吸。由于适体与金黄色葡萄球菌具有很强的结合能力，因此形成了带有长双荧光分子标记的双链 DNA 产物，从而产生了双信号读出响应（信号开启）。因此，该传感器可用于一步法定量检测 10 至 10 CFU/mL 范围内的金黄色葡萄球菌浓度，检测限为 1 CFU/mL，具有可靠、灵敏和选择性。此外，在牛奶样品中具有良好的稳定性、重现性、特异性和良好的回收率，表明该传感器可作为食品安全分析的一种有前途的工具。
