Background: Immunoglobulin A (IgA) accounts for 15% of total protein production per day and plays a crucial role in the first-line immune defence. Recently, IgA has been established as a vital clinical biomarker for nephropathy, allergic asthma, celiac disease (CD), pneumonia, and asthma as well as some neurological disorders. In this work, we have studied several carbon nanomaterials (CNMs) having different dimensions (D): carbon nano-onions (CNOs) - 0D, single-walled carbon nanotubes (SWCNTs) - 1D, and graphene nanoplatelets (GNPs) - 2D, on glassy carbon electrode (GCE) to identify which CNMs (CNOs/SWCNTs/GNPs) work best to fabricate IgA based electrochemical immunosensor.

Methods: Different CNMs (CNOs, SWCNTs, GNPs) were tested for high electric current on GCE using square wave voltammetry (SWV), and among them, GNPs modified GCE platform (GNPs/GCE) showcased the highest electric current. Therefore, GNPs/GCE was utilized for the development of highly sensitive label-free electrochemical immunosensor for the detection of Immunoglobulin A using SWV.

Results: Despite the simple fabrication strategies employed, the fabricated sensor demonstrated a low limit of detection of 50 fg mL-1 with an extensive linear range of detection from 50 fg mL-1 to 0.1 μg mL-1.

Conclusion: Fabricated immunosensor represented high stability, repeatability, specificity and resistance to most common interferences as well as great potential to analyse the real sample.

背景：免疫球蛋白A（IgA）每天占蛋白质总产量的15％，在一线免疫防御中起着至关重要的作用。最近，IgA已被确立为肾病，过敏性哮喘，腹腔疾病（CD），肺炎和哮喘以及某些神经系统疾病的重要临床生物标志物。在这项工作中，我们研究了几种具有不同尺寸（D）的碳纳米材料（CNM）：碳纳米洋葱（CNO）-0D，单壁碳纳米管（SWCNT）-1D和石墨烯纳米片（GNP）-2D，在玻璃碳电极（GCE）上进行鉴定，以确定哪种CNM（CNO / SWCNTs / GNP）最适合制造基于IgA的电化学免疫传感器。

方法：使用方波伏安法（SWV）在GCE上测试了不同的CNM（CNO，SWCNT，GNP）的高电流，其中，GNP改良的GCE平台（GNPs / GCE）展示了最高的电流。因此，GNPs / GCE被用于开发高度灵敏的无标记电化学免疫传感器，用于使用SWV检测免疫球蛋白A。

结果：尽管采用了简单的制造策略，但制造出的传感器仍显示出50 fg mL-1的低检测限，并具有从50 fg mL-1到0.1μgmL-1的广泛线性检测范围。

结论：制备的免疫传感器具有很高的稳定性，可重复性，特异性和对大多数常见干扰的抵抗力，并且具有分析真实样品的巨大潜力。