Cheng Guangmin, Bai Wenlong, Zhang Xuanming, Xia Xuan, Zhang Tao, Feng Dong, Wei Lei, Wang Chongwen, Wang Shu, Zheng Shuai
Department of Nephrology, First Affiliated Hospital of Anhui Medical University, Hefei, China.
Hefei Institute of Physical Science, Chinese Academy of Sciences, Hefei, 230036, China.
Mikrochim Acta. 2025 Sep 17;192(10):675. doi: 10.1007/s00604-025-07531-0.
To address the challenges of poor system compatibility, low sensitivity, and narrow detection range in traditional colorimetric lateral flow immunochromatographic assay (LFA) for dynamic monitoring of urinary tract infection (UTI) pathogens (biomacromolecules) and antibiotics (small molecules), we propose a colorimetric-enhanced LFA technique based on monodisperse bimetallic composite nanozymes (Si@D(AuPt)), achieving rapid and precise detection of different types of markers in real urinary tract infection samples. The raspberry-like Si@D(AuPt) nanozyme employs a highly stable SiO core, with continuous loading of double-layer dense AuPt nanoparticles to provide rough surface area and dense spatial catalytic sites, greatly enhancing the complex sample stability and peroxidase activity of single nanolabel. Furthermore, efficient and stable antibody-nanomaterial coupling was achieved through 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) molecule mediation, improving the universal detection capability and accuracy of the LFA system. Experimental results show that the platform achieves detection Limits of 11.64 cells/mL for Pseudomonas aeruginosa (sandwich mode), 6.70 pg/mL for gentamicin, and 3.69 pg/mL for cefalexin (competitive mode), with sensitivity at least 400 times higher than traditional colloidal AuNP-based LFA strips. Additionally, the proposed assay demonstrates excellent stability, sensitivity, and specificity in actual urine samples, providing a reliable technical means for real-time monitoring of UTI related indicators.
为应对传统比色侧向流动免疫层析分析（LFA）在动态监测尿路感染（UTI）病原体（生物大分子）和抗生素（小分子）时存在的系统兼容性差、灵敏度低和检测范围窄等挑战，我们提出了一种基于单分散双金属复合纳米酶（Si@D(AuPt)）的比色增强LFA技术，可在实际尿路感染样本中快速、精确地检测不同类型的标志物。树莓状的Si@D(AuPt)纳米酶采用高度稳定的SiO核，连续负载双层致密的AuPt纳米颗粒，以提供粗糙的表面积和密集的空间催化位点，大大增强了单个纳米标记物在复杂样本中的稳定性和过氧化物酶活性。此外，通过5,5'-二硫代双（2-硝基苯甲酸）（DTNB）分子介导实现了高效稳定的抗体-纳米材料偶联，提高了LFA系统的通用检测能力和准确性。实验结果表明，该平台对铜绿假单胞菌的检测限为11.64个细胞/mL（夹心模式），对庆大霉素为6.70 pg/mL，对头孢氨苄为3.69 pg/mL（竞争模式），灵敏度比传统基于胶体金纳米颗粒的LFA试纸至少高400倍。此外，所提出的分析方法在实际尿液样本中表现出优异的稳定性、灵敏度和特异性，为实时监测UTI相关指标提供了可靠的技术手段。
