For the first time, a novel NiFe₂O₄/paper-based magnetoelastic (ME) biosensor was developed for rapid, sensitive, and portable detection of human serum albumin (HSA). Due to the uniquely magnetoelastic effect of NiFe₂O₄ nanoparticles and the excellent mechanical properties of the paper, the paper-based ME biosensor transforms the surface stress signal induced by the specific binding of HSA and antibody modified on the paper into the electromagnetic signal. The accumulated binding complex generates a compressive stress on the biosensor surface, resulting in a decrease in the biosensor’s static magnetic permeability, which correlates to the HSA concentrations. To improve the sensitivity of the biosensor, the concentration of NiFe₂O₄ nanofluid and the impregnated numbers of the NiFe₂O₄ nanofluid-impregnated papers were optimized. The experimental results demonstrated that the biosensor exhibited a linear response to HSA concentrations ranging from 10 μg∙mL⁻¹ to 200 μg∙mL⁻¹, with a detection limit of 0.43 μg∙mL⁻¹, which is significantly lower than the minimal diagnosis limit of microalbuminuria. The NiFe₂O₄/paper-based ME biosensor is easy to fabricate, and allows the rapid, highly-sensitive, and selective detection of HSA, providing a valuable analytical device for early monitoring and clinical diagnosis of microalbuminuria and nephropathy. This study shows the successful integration of the paper-based biosensor and the ME sensing analytical method will be a highly-sensitive, easy-to-use, disposable, and portable alternative for point-of-care monitoring.

中文翻译：

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一种用于检测人血清白蛋白的新型 NiFe2O4/纸基磁弹性生物传感器。


首次开发了一种新型NiFe ₂ O ₄ /纸基磁弹性（ME）生物传感器，用于快速、灵敏和便携式检测人血清白蛋白（HSA）。由于NiFe ₂ O ₄纳米颗粒独特的磁弹性效应和纸张优异的机械性能，纸基ME生物传感器将HSA与纸张上修饰的抗体特异性结合引起的表面应力信号转化为电磁信号。积累的结合复合物在生物传感器表面产生压应力，导致生物传感器的静磁导率降低，这与 HSA 浓度相关。为了提高生物传感器的灵敏度，对NiFe ₂ O ₄纳米流体的浓度和NiFe ₂ O ₄纳米流体浸渍纸的浸渍数量进行了优化。实验结果表明，该生物传感器对HSA浓度范围为10 μg∙mL ⁻¹至200 μg∙mL ⁻¹表现出线性响应，检测限为0.43 μg∙mL ⁻¹ ，显着低于最低诊断值微量白蛋白尿的限度。 NiFe ₂ O ₄ /纸基ME生物传感器易于制造，能够快速、高灵敏度、选择性地检测HSA，为微量白蛋白尿和肾病的早期监测和临床诊断提供了有价值的分析装置。这项研究表明，纸基生物传感器和 ME 传感分析方法的成功集成将成为一种高灵敏度、易于使用、一次性和便携式的即时监测替代方案。