Immobilizing matrix plays a crucial role in anchoring the receptors of target biomolecules and enhancing the sensing capability of biosensor. Howbeit, the immobilization platforms that induce stable molecular interactions with the receptors without the need for harsh reaction conditions (covalent bonding) are rare. Herein, we report the design, development and application of novel semiconducting one-dimensional (1D) tetrazine polymers (TTz, PhTTz, PhAlkTz) as immobilizing matrices for electronic biosensing of carcinoembryonic antigen (CEA), a cancer biomarker. The polymers are fully loaded with electron-deficient tetrazine units (nitrogen-rich), which develop strong hydrogen bonding (H-bonding) interactions and effectively immobilize the bioreceptor (anti-CEA). The sensor comprises reduced graphene oxide (rGO) as the base conducting layer and tetrazine polymers as immobilizing matrices for the CEA antibodies. The rGO/TTz/anti-CEA, rGO/PhTTz/anti-CEA, rGO/PhAlkTz/anti-CEA sensors exhibited 3.5 to 34.16 μA, 2.2 to 34.89 μA, 1.1 to 39.27 μA responses, respectively, for 1 pg/ml to 200 ng/ml of CEA. The sensors' (TTz, PhTTz, and PhAlkTz) sensitivities, selectivities and stabilities are found to be better than that of previously reported partially tetrazine loaded polymer (PhPTz). The study discloses the presence of H-bonding in tetrazine units is highly critical for superior sensing. The concept of utilizing N-rich tetrazine units in the immobilizing platforms can be generalized to several other hetero-atom based systems and polymers. Thus, a wide variety of novel immobilizing substrates can be developed to realize superior sensing performance.

中文翻译：

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基于半导体四嗪聚合物的固定基质的结构定制用于癌胚抗原的优异电子生物传感

固定化基质在锚定目标生物分子的受体和增强生物传感器的传感能力方面起着至关重要的作用。然而，无需苛刻的反应条件（共价键合）即可诱导与受体稳定分子相互作用的固定化平台很少见。在此，我们报道了新型半导体一维 (1D) 四嗪聚合物 ( TTz、PhTTz、PhAlkTz ) 的设计、开发和应用) 作为用于癌胚抗原 (CEA)（一种癌症生物标志物）电子生物传感的固定基质。聚合物中满载缺电子四嗪单元（富氮），可形成强氢键（H 键）相互作用并有效固定生物受体（抗 CEA）。该传感器包含还原氧化石墨烯 (rGO) 作为基础导电层和四嗪聚合物作为 CEA 抗体的固定基质。对于1 pg / ml至_ 200 纳克/毫升 CEA。传感器的（TTz、PhTTz和PhAlkTz) 的灵敏度、选择性和稳定性被发现优于先前报道的部分四嗪负载聚合物 ( PhPTz )。该研究表明，四嗪单元中氢键的存在对于卓越的传感非常关键。在固定化平台中利用富氮四嗪单元的概念可以推广到其他几种基于杂原子的系统和聚合物。因此，可以开发各种各样的新型固定底物以实现卓越的传感性能。