Chanarsa Supakeit, Yaiwong Patrawadee, Anuthum Siriporn, Chanawanno Kullapa, Jakmunee Jaroon, Ounnunkad Kontad
Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Center of Excellence for Innovation in Chemistry, Chiang Mai University, Chiang Mai 50200, Thailand.
ACS Meas Sci Au. 2025 May 15;5(3):388-396. doi: 10.1021/acsmeasuresciau.5c00048. eCollection 2025 Jun 18.
Neuroendocrine tumors (NETs), often misdiagnosed and mistreated, require early detection for precise therapeutic interventions. This study presents a newly developed competitive electrochemical immunosensor for sensitive and selective detection of chromogranin A (CgA), a key biomarker for diagnosing and monitoring NETs. The sensor, featuring a sandwiched structure with versatile and multifunctional graphene oxide (GO), utilizes polyethylenimine-capped gold nanoparticles (PEI-AuNPs) to enhance the electroreactivity and biocompatibility of a screen-printed electrode (SPE). The immunosensor operates by immobilizing standard CgA antigens on the PEI-AuNPs/GO-modified SPE surface and employing GO nanotags loaded with anti-CgA antibodies (Ab) and ferrocene monocarboxylic acid (Fc) redox probes to capture target CgA. As the CgA concentration increases, the current response of the immunosensor decreases due to a reduction in the amount of Fc/Ab/GO tags on the electrode surface. This reduction occurs because the nanotags bind to the free CgA in the sample rather than the CgA immobilized on the electrode. The immunosensor demonstrates a good linearity (0.10-50 ng mL), a low detection limit of 90 pg mL, and high accuracy in detecting CgA levels in human serum samples. With its high specificity, long-term stability, and excellent reproducibility, our cost-effective and user-friendly platform holds promise for clinical screening and point-of-care diagnosis of NETs. Further optimization of the immunosensor's design and exploration of its use for additional biomarkers could enhance NETs' diagnosis and provide advancements in managing other related health conditions.
神经内分泌肿瘤（NETs）常常被误诊和误治，需要早期检测以便进行精准的治疗干预。本研究展示了一种新开发的竞争性电化学免疫传感器，用于灵敏且选择性地检测嗜铬粒蛋白A（CgA），这是一种用于诊断和监测NETs的关键生物标志物。该传感器具有一种夹心法结构，采用了多功能的氧化石墨烯（GO），利用聚乙烯亚胺包覆的金纳米粒子（PEI-AuNPs）来增强丝网印刷电极（SPE）的电活性和生物相容性。该免疫传感器的工作原理是将标准CgA抗原固定在PEI-AuNPs/GO修饰的SPE表面，并使用负载有抗CgA抗体（Ab）和二茂铁单羧酸（Fc）氧化还原探针的GO纳米标签来捕获目标CgA。随着CgA浓度的增加，免疫传感器的电流响应降低，这是由于电极表面Fc/Ab/GO标签数量的减少。这种减少的发生是因为纳米标签与样品中的游离CgA结合，而不是与固定在电极上的CgA结合。该免疫传感器表现出良好的线性（0.10 - 50 ng/mL），90 pg/mL的低检测限，以及在检测人血清样品中CgA水平时的高精度。凭借其高特异性、长期稳定性和出色的重现性，我们这个经济高效且用户友好的平台有望用于NETs的临床筛查和即时诊断。进一步优化免疫传感器的设计并探索其用于其他生物标志物的用途，可能会提高NETs的诊断水平，并在管理其他相关健康状况方面取得进展。
