Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, School of Environment and Health, Jianghan University, Wuhan, 430056, China.
Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, College of Photoelectric Materials and Technology, Jianghan University, Wuhan, 430056, China.
Mikrochim Acta. 2024 Jul 15;191(8):464. doi: 10.1007/s00604-024-06539-2.
Rapid and high-sensitive Salmonella detection in milk is important for preventing foodborne disease eruption. To overcome the influence of the complex ingredients in milk on the sensitive detection of Salmonella, a dual-signal reporter red fluorescence nanosphere (RNs)-Pt was designed by combining RNs and Pt nanoparticles. After being equipped with antibodies, the immune RNs-Pt (IRNs-Pt) provide an ultra-strong fluorescence signal when excited by UV light. With the assistance of the HO/TMB system, a visible color change appeared that was attributed to the strong peroxidase-like catalytic activity derived from Pt nanoparticles. The IRNs-Pt in conjunction with immune magnetic beads can realize that Salmonella typhimurium (S. typhi) was captured, labeled, and separated effectively from untreated reduced-fat pure milk samples. Under the optimal experimental conditions, with the assay, as low as 50 CFU S. typhi can be converted to detectable fluorescence and absorbance signals within 2 h, suggesting the feasibility of practical application of the assay. Meanwhile, dual-signal modes of quantitative detection were realized. For fluorescence signal detection (emission at 615 nm), the linear correlation between signal intensity and the concentration of S. typhi was Y = 83C-3321 (R = 0.9941), ranging from 10 to 10 CFU/mL, while for colorimetric detection (absorbamce at 450 nm), the relationship between signal intensity and the concentration of S. typhi was Y = 2.9logC-10.2 (R = 0.9875), ranging from 5 × 10 to 10 CFU/mL. For suspect food contamination by foodborne pathogens, this dual-mode signal readout assay is promising for achieving the aim of convenient preliminary screening and accurate quantification simultaneously.
快速且高灵敏度地检测牛奶中的沙门氏菌对于预防食源性疾病的爆发非常重要。为了克服牛奶中复杂成分对沙门氏菌敏感检测的影响，设计了一种双信号报告红色荧光纳米球（RNs）-Pt，它是通过将 RNs 和 Pt 纳米粒子结合而成的。经过抗体修饰后，当受到紫外光激发时，免疫 RNs-Pt（IRNs-Pt）会产生超强的荧光信号。在 HO/TMB 体系的辅助下，出现了可见的颜色变化，这归因于 Pt 纳米粒子所具有的强烈过氧化物酶样催化活性。IRNs-Pt 与免疫磁珠结合，可以有效地从未经处理的低脂纯牛奶样品中捕获、标记和分离鼠伤寒沙门氏菌（S. typhi）。在最佳实验条件下，该检测方法可以在 2 小时内将低至 50 CFU 的 S. typhi 转化为可检测的荧光和吸光度信号，表明该检测方法具有实际应用的可行性。同时，实现了双信号定量检测模式。对于荧光信号检测（发射波长为 615nm），信号强度与 S. typhi 浓度之间的线性相关关系为 Y=83C-3321（R=0.9941），范围为 10 至 10 CFU/mL，而对于比色检测（吸收波长为 450nm），信号强度与 S. typhi 浓度之间的关系为 Y=2.9logC-10.2（R=0.9875），范围为 5×10 至 10 CFU/mL。对于食源性致病菌污染的可疑食品，这种双模式信号读取检测方法有望实现方便的初步筛选和准确的定量同时进行的目标。
