Early detection of immunoglobin G (IgG), a glycoprotein antibody produced in the serum due to various infections, is of paramount importance that will enable effective treatment, immunity assessment, and assist in monitoring outbreaks of contagious diseases. This work demonstrates the transverse magneto-optic Kerr effect (T-MOKE) based magnetoplasmons excited on a composite ferromagnetic/plasmonic grating as a highly sensitive, single wavelength, and target specific biosensing platform. The sharp T-MOKE sensitivity curve corresponding to reduced fwhm results in a two orders of magnitude enhancement in the resolving power compared to conventional propagating surface plasmon polariton (SPP), which is pivotal in identifying minute fluctuations in specific biomolecular concentrations. An order of magnitude improvement in antibody immunoglobin G (IgG) detection limit is observed compared to the SPP based sensing. A detection limit down to 10 ng/mL (66 pM) is achieved using the proposed T-MOKE technique. The results obtained provide compelling evidence of the significantly superior sensitivity and resolving power of the T-MOKE technique for the detection of Human IgG, and it is envisioned that this spectroscopy free, single wavelength measurement approach can be extended to detect biologically/chemically relevant molecules at lower concentrations for early biomedical diagnosis and therapy.

中文翻译：

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磁等离子体激元用于超灵敏的无标记生物传感

尽早发现免疫球蛋白G（IgG）是一种因各种感染而在血清中产生的糖蛋白抗体，具有极为重要的意义，它将能够进行有效的治疗，评估免疫力并协助监测传染性疾病的爆发。这项工作演示了在复合铁磁/等离激元光栅上激发的基于横向磁光克尔效应（T-MOKE）的磁等离子体，作为高灵敏度，单波长和目标特定的生物传感平台。与常规的传播表面等离振子极化子（SPP）相比，对应于降低的fwhm的尖锐的T-MOKE敏感度曲线导致了分辨能力的提高两个数量级，这对于确定特定生物分子浓度的微小波动至关重要。与基于SPP的传感相比，可以观察到抗体免疫球蛋白G（IgG）检测极限的数量级提高。使用建议的T-MOKE技术可实现低至10 ng / mL（66 pM）的检测限。所获得的结果提供了令人信服的证据，证明T-MOKE技术对人IgG的检测具有显着优越的灵敏度和分辨能力，并且可以预见，这种无光谱的单波长测量方法可以扩展为检测生物/化学相关分子以较低的浓度进行早期生物医学诊断和治疗。