Motivation behind the present work is to fabricate a cost effective and scalable biosensing platform for an easy and reliable detection of cancer biomarker Carcinoembryonic antigen (CEA). Here, we report the sensitive and selective detection of CEA using graphene based bio-sensing platform. Large sized (~ 2.5 × 1.0 cm²), uniform, continuous, single and few layers graphene films have been grown on copper (Cu) substrate employing chemical vapor deposition (CVD) technique using hexane as a liquid precursor. Functional group has been created over Graphene/Cu substrate through π-π stacking of 1- pyrenebutanoic acid succinimidyl ester (PBSE). Further, to make the sensor specific to CEA, antibody of CEA (anti-CEA) has been covalently immobilized onto PBSE/Graphene/Cu electrode. Selective and sensitive detection of CEA is achieved by anti-CEA/PBSE/Graphene/Cu electrode through electrochemical impedance spectroscopy (EIS) measurements. Under optimal condition, the fabricated sensor shows linear response in the physiological range 1.0–25.0 ng mL⁻¹ (normal value ~ 5.0 ng mL⁻¹), revealing sensitivity 563.4 Ω ng⁻¹ mL cm⁻² with a correlation coefficient of 0.996 and limit of detection (LOD) 0.23 ng mL⁻¹. In this way, one step electrode fabrication with high specific surface area provides a light weight, low cost, reliable and scalable novel biosensing platform for sensitive and selective detection of CEA. We believe that this bioelectrode equipped with specific recognition elements could be utilized for detection of other biomolecules too.

本工作背后的动机是制造一种经济高效且可扩展的生物传感平台，以轻松，可靠地检测癌症生物标记癌胚抗原（CEA）。在这里，我们报告使用基于石墨烯的生物传感平台对CEA进行灵敏和选择性的检测。大号（〜2.5×1.0 cm ²），均匀，连续，单层和很少层的石墨烯薄膜已通过使用己烷作为液体前体的化学气相沉积（CVD）技术在铜（Cu）基板上生长。通过1- pyr丁酸丁二酰亚胺基酯（PBSE）的π-π堆积，在石墨烯/ Cu底物上创建了官能团。此外，为了使传感器对CEA具有特异性，已经将CEA的抗体（抗CEA）共价固定在PBSE /石墨烯/ Cu电极上。通过抗CEA / PBSE /石墨烯/ Cu电极通过电化学阻抗谱（EIS）测量来实现CEA的选择性和灵敏检测。在最佳条件下，制成的传感器在1.0–25.0 ng mL ^-1的生理范围内显示线性响应（正常值〜5.0 ng mL ^-1），灵敏度为563.4Ωng ^-1  mL cm ^-2，相关系数为0.996，检出限（LOD）为0.23 ng mL ^-1。以此方式，具有高比表面积的一步式电极制造提供了重量轻，成本低，可靠且可扩展的新型生物传感平台，用于CEA的灵敏和选择性检测。我们相信，这种配备有特定识别元件的生物电极也可以用于检测其他生物分子。