肉眼
检出限
化学
沙门氏菌
比色法
吸光度
超顺磁性
适体
螯合作用
纳米颗粒
显色的
阿布茨
线性范围
色谱法
纳米技术
材料科学
生物化学
分子生物学
细菌
抗氧化剂
生物
物理
磁化
量子力学
磁场
遗传学
有机化学
DPPH
作者
Yu Zhang,Mingfu Gong,Xiang Li,Hongyu Liu,Penghui Liang,Shuhua Cui,Liang Zhang,Chunyu Zhou,Tao Sun,Maosheng Zhang,Cong-Ying Wen,Jingbin Zeng
标识
DOI:10.1016/j.jhazmat.2022.129140
摘要
In this work, we developed an ultrasensitive colorimetry for Salmonella typhimurium detection with multifunctional Au-Fe3O4 dumbbell-like nanoparticles (DBNPs) which possessed easy bio-modifiability, excellent LSPR characteristics, superparamagnetic properties and super peroxidase-like activity. In the detection, the anti-S. typhimurium antibody modified DBNPs (IDBNPs) bound with S. typhimurium and aggregated on their surfaces in a large number, which showed much quicker magnetic response than free IDBNPs. By controlling appropriate separation conditions, IDBNPs@S. typhimurium composites were captured, while free IDBNPs were remained in the supernatant. Therefore, by detecting the absorbance of the supernatant, quantitative detection was achieved from 10 to 1000 CFU/mL. Moreover, utilizing the peroxidase-like activity of IDBNPs, we further realized semi-quantitative naked-eye detection. By adding ABTS into the above supernatant, which was oxidized to green chelate (OxABTS), colorimetric signal was amplified significantly, and meanwhile, the green chelates and the wine-red IDBNPs engendered mixed color, enhancing the range of color gradation and greatly improving the visual resolution. Finally, a detection limit (10 CFU/mL) comparable with that of above spectrum measurement was achieved. Besides, our method exhibited efficient capture capability (nearly 100% even for rare S. typhimurium), and had good stability and specificity, and acceptable anti-interference ability in fetal bovine serum and milk samples.
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