Anhui Province Key Laboratory of Biomedical Materials and Chemical Measurement, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, China.
Luminescence. 2024 Jul;39(7):e4829. doi: 10.1002/bio.4829.
A ratio luminescence probe was developed for detecting Staphylococcus aureus (S. aureus) based on luminescence energy transfer (LET) using double-wavelength emission (550 nm and 812 nm) upconversion nanoparticles (UCNPs) as donor, gold nanoparticles (AuNPs) as acceptor and the aptamer for S. aureus as the specific recognition and link unit. The LET process could cause luminescence quenching because of the spectral overlap between the acceptor and the donor at 550 nm. In the presence of S. aureus, S. aureus selectively combined with the aptamer, and the AuNPs left the surface of UCNPs, which weakened the quenching effect and restored the luminescence of UCNPs. Based on this, the ratio detection was realized by monitoring the change of the luminescence signal of the probe at 550 nm and taking the luminescence signal at 812 nm as the reference signal. Crucially, the probe has a fast reaction speed, with a reaction time of 25 min, and the detection of S. aureus is realized in the concentration range of 5.0 × 10-3.0 × 10 CFU/ml, with the detection limit of 106 CFU/ml. Therefore, the ratio probe has great potential for detecting of S. aureus in food because of its high sensitivity, fast speed and good selectivity.
基于上转换纳米粒子（UCNPs）作为供体、金纳米粒子（AuNPs）作为受体以及金黄色葡萄球菌（S. aureus）适配体作为特异性识别和连接单元的双波长发射（550nm 和 812nm）的发光能量转移（LET），开发了一种用于检测金黄色葡萄球菌的比率荧光探针。LET 过程会导致荧光猝灭，因为在 550nm 处受体和供体之间存在光谱重叠。在存在金黄色葡萄球菌的情况下，金黄色葡萄球菌选择性地与适配体结合，AuNPs 离开 UCNPs 的表面，从而减弱猝灭效应并恢复 UCNPs 的发光。基于此，通过监测探针在 550nm 处的荧光信号变化并以 812nm 处的荧光信号作为参考信号，实现了比率检测。关键的是，该探针具有快速的反应速度，反应时间为 25min，在 5.0×10-3.0×10 CFU/ml 的浓度范围内实现了对金黄色葡萄球菌的检测，检测限为 106 CFU/ml。因此，该比率探针具有高灵敏度、快速速度和良好选择性，在食品中检测金黄色葡萄球菌具有很大的潜力。
