β-乳球蛋白光热免疫层析试纸条的研制

Development of photothermal immunochromatographic test strips forβ-lactoglobulin

目的研制β-乳球蛋白(β-lactoglobulin,β-Lg)光热免疫层析试纸条。方法合成了具有高光热转换效率(η=47.5%)的硫化钴-单宁酸(cobalt sulfide-tannic acid,CoS@TA)纳米球,并将其与多克隆抗体偶联制备光热免疫探针,同时优化了抗体标记量、抗体包被浓度以及试纸条的各项工作条件,在此基础上建立了一种基于CoS@TA的β-Lg光热免疫层析试纸条(photothermal immuno-chromatographic test strip,PITS)检测方法。结果该免疫层析法中视觉检出限为250μg/L,光热检出限为26.44μg/L,比视觉检出限高出9.5倍,同时具有良好的特异性,并通过在婴幼儿氨基酸奶粉中的添加回收实验和商用酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)试剂盒验证了该方法在实际样品检测中的有效性。结论该方法使用便携仪器即可实现对β-Lg的快速、高灵敏定量检测,可用于奶粉的快速检测。

Objective To develop photothermal immunochromatographic test strips forβ-lactoglobulin(β-Lg).Methods The cobalt sulfide-tannic acid(CoS@TA)nanospheres with high photothermal conversion efficiency(η=47.5%)were synthesized and coupled with polyclonal antibodies to prepare photothermal immunoprobes,and the amount of antibody label,concentration of antibody encapsulation,and working conditions of the test strips were optimized.A photothermal immunochromatographic test strip(PITS)method based on CoS@TA was established.Results The immunochromatographic method had a visual detection limit of 250μg/L and a photothermal detection limit of 26.44μg/L,which was 9.5 times higher than the visual detection limit,and also had good specificity,which was validated by the spiked recovery experiment in infant amino acid milk powder and a commercial enzyme-linked immunosorbent assay(ELISA)kit.Conclusion The method can realize rapid and highly sensitive quantitative detection ofβ-Lg using a portable instrument,and can be used for rapid detection of infant formula.