In this study, a high-performance anti-fouling coating based on poly adenine (polyA_n) as well as a highly specific cluster of differentiation 20 (CD20) epitope mimetic peptide (CN14) were employed to synergistically construct a facile biosensor for the rapid and sensitive determination of rituximab in lymphoma patients' plasma. The well-designed and optimized polyA_n coating displayed excellent stability, hydrophilicity, thanks to its intrinsic affinity with gold surface and thoroughly exposed hydrophilic phosphate groups. Moreover, the proposed strategy avoids the necessity to modify binding groups (e.g. thiol), making it more facile, repeatable and efficient. When dealing with complex clinical plasma samples, the polyA_n coating demonstrated better anti-fouling performance and lower background signal in comparison with mercaptan and bovine serum albumin coatings. The dissociation constant (∼60 nM) between CN14 and rituximab was measured by microscale thermophoresis and their binding mechanism was further explained using computer simulation. The constructed GE/CN14/polyA₂₀ biosensor displayed satisfactory performance with detection limit of 35.26 ng/mL. Finally, the proposed biosensor was successfully applied for rapidly determining rituximab in lymphoma patients' plasma, and exhibited comparable accuracy to the commercial ELISA, but has advantages including a shorter detection time, wider detection range and lower cost. It's worth noting that the anti-fouling polyA_n coating can be tailored according to the surface property of sensing interface and can be easily expanded to other gold electrode related biosensors.

在这项研究中，基于聚腺嘌呤（polyA _n）的高性能防污涂层以及分化特异性20（CD20）表位模拟肽（CN14）的高度特异性簇被用于协同构建快速快速的生物传感器。和敏感性测定淋巴瘤患者血浆中的利妥昔单抗。经过精心设计和优化的polyA _n涂层具有出色的稳定性和亲水性，这归功于其与金表面的固有亲和力以及充分暴露的亲水性磷酸基团。而且，所提出的策略避免了修饰结合基团（例如硫醇）的必要性，使其更容易，可重复和有效。当处理复杂的临床血浆样品时，polyA _n与硫醇和牛血清白蛋白涂料相比，该涂料具有更好的防污性能和较低的背景信号。CN14和利妥昔单抗之间的解离常数（〜60 nM）通过微尺度热泳法测量，并通过计算机模拟进一步解释其结合机理。构建的GE / CN14 / polyA ₂₀生物传感器显示出令人满意的性能，检测极限为35.26 ng / mL。最终，所提出的生物传感器成功地用于快速测定淋巴瘤患者血浆中的利妥昔单抗，并具有与商业ELISA相当的准确性，但具有检测时间更短，检测范围更广，成本更低的优点。值得一提的是，防污聚腺苷酸_ñ 可以根据传感界面的表面特性定制涂层，并且可以轻松扩展到其他与金电极相关的生物传感器。