College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China.
School of Life Sciences, Longyan University, Longyan 364012, China.
Molecules. 2023 Apr 16;28(8):3502. doi: 10.3390/molecules28083502.
β-lactoglobulin (β-Lg) is a protein found in milk that can cause severe allergic reactions, including rash, vomiting, and diarrhea. Thus, it is crucial to develop a sensitive β-Lg detection method to protect people who are susceptible to allergies. Here, we introduce a novel and highly sensitive fluorescent aptamer biosensor for detecting β-Lg. First, a fluorescein-based dye (FAM)-labeled β-lactoglobulin aptamer (β-Lg aptamer) is adsorbed on the surface of tungsten disulfide (WS) nanosheets via van der Waals forces, resulting in fluorescence quenching. When β-Lg is present, the β-Lg aptamer selectively binds to β-Lg, causing a conformational change in the β-Lg aptamer and releasing it from the surface of WS nanosheets, which restores the fluorescence signal. Simultaneously, DNase I in the system cleaves the aptamer bound to the target, producing a short oligonucleotide fragment and releasing β-Lg. The released β-Lg then binds to another β-Lg aptamer adsorbed on WS, initiating the next round of cleavage, resulting in significant amplification of the fluorescence signal. This method has a linear detection range of 1-100 ng mL, and the limit of detection is 0.344 ng mL. Furthermore, this approach has been successfully used for detecting β-Lg in milk samples with satisfactory results, providing new opportunities for food analysis and quality control.
β-乳球蛋白（β-Lg）是牛奶中的一种蛋白质，可引起严重的过敏反应，包括皮疹、呕吐和腹泻。因此，开发一种敏感的β-Lg 检测方法对于保护易过敏的人群至关重要。在这里，我们介绍了一种用于检测β-Lg 的新型高灵敏度荧光适体生物传感器。首先，通过范德华力将荧光素标记的β-乳球蛋白适体（β-Lg 适体）吸附在二硫化钨（WS）纳米片的表面上，导致荧光猝灭。当存在β-Lg 时，β-Lg 适体选择性地与β-Lg 结合，导致β-Lg 适体构象发生变化，并从 WS 纳米片表面释放出来，从而恢复荧光信号。同时，体系中的 DNase I 切割与靶标结合的适体，产生短的寡核苷酸片段并释放β-Lg。释放的β-Lg 然后与吸附在 WS 上的另一个β-Lg 适体结合，引发下一轮切割，导致荧光信号显著放大。该方法的线性检测范围为 1-100ng/mL，检测限为 0.344ng/mL。此外，该方法已成功用于检测牛奶样品中的β-Lg，结果令人满意，为食品分析和质量控制提供了新的机会。
