提出简便、灵敏的DNA碱基检测方法对生物分析和医学诊断具有重要意义。在这里,通过使用均苯四甲酸二酐(PMDA)和三(4-氨基苯基)胺(TAPA)的溶剂热法成功合成了高度结晶的聚酰亚胺共价有机骨架(TAPM-COF),具有较大的比表面积(2286m2g-1)和优异的热稳定性。有趣的是,随着反应介质中含水量的增加,TAPM-COF的结晶度显著提高。为了验证这种现象,我们通过均苯四甲酸二酐(PMDA)和N,N,N\',N'-四(4-氨基苯基)-1,4-苯二胺(TPDA),该结合类似于TAPM-COF。此外,制备的TAPM-COF-0.3用于在玻碳电极上构建一种新型的独立电化学生物传感器,用于在不添加其他添加剂的情况下同时测定腺嘌呤(A)和鸟嘌呤(G)。然而,为了进一步提高TAPM-COF在电化学传感中的信号,结晶TAPM-COF-0.3可以容易地与氨基官能化的多壁碳纳米管(NH2-MWCNT)整合以形成由π-π堆叠相互作用驱动的核-壳TAPM-COF-0.3@NH2-MWCNT,用于对嘌呤碱更灵敏的电化学传感。与TAPM-COF/GCE相比,TAPM-COF@NH2-MWCNT/GCE具有较好的线性范围和较低的检测限。该工作为电化学传感器领域的COF信号放大提供了一种新的策略。
It is of great significance to propose simple methods to detect DNA bases sensitively for biological analysis and medical diagnosis. Herein, a highly crystalline polyimide covalent organic framework (TAPM-COF) has been successfully synthesized via a solvothermal route using pyromellitic dianhydride (PMDA) and tris(4-aminophenyl) amine (TAPA), which possessed large specific surface area (2286 m2 g-1) and excellent thermal stability. Intriguingly, the crystallinity of the TAPM-COF improved significantly with the increase of water content in the reaction medium. To verify this phenomenon, we synthesized TPPM-COF with two pores by pyromellitic dianhydride (PMDA) and N,N,N\',N\'-tetrakis(4-aminophenyl)-1,4-benzenediamine (TPDA), which bonding was similar to TAPM-COF. Furthermore, the prepared TAPM-COF-0.3 was used to construct a novel and independent electrochemical biosensor on glassy carbon electrode for simultaneously determination of adenine (A) and guanine (G) without other additives. However, to further improve signal of TAPM-COF in electrochemical sensing, the crystalline TAPM-COF-0.3 can be readily integrated with amino-functionalized multiwalled carbon nanotubes (NH2-MWCNT) to form core-shell TAPM-COF-0.3@NH2-MWCNT driven by a π-π stacking interaction for more sensitive electrochemical sensing toward purine bases. In comparison to TAPM-COF/GCE, the TAPM-COF@NH2-MWCNT/GCE exhibited more favorable linear range and lower limit of detection. The work provided a new strategy for amplifying signal of COF in the field of electrochemical sensors.