College of Material and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu, 610059, China.
College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China.
Mikrochim Acta. 2020 Aug 1;187(8):477. doi: 10.1007/s00604-020-04392-7.
An ultrasensitive O-based electrochemical aptasensor by on-line assembly of photosensitizers using graphene oxide (GO) as a cartridge is reported. In the presence of target protein lysozyme, the interaction of lysozyme with aptamer led to the dissociation of dsDNA and release of the aptamer-lysozyme complex to solution, with DNA-c retaining on the electrode; then, the photosensitizer phloxine B (PB) was assembled on the electrode since GO can simultaneously adsorb DNA-c and PB molecules. Upon irradiation by a green LED, O was generated by photocatalysis of PB molecules and then cleaved the DNA-c, leading to remarkably decreased impedance signals that linearly respond with the logarithm of lysozyme concentration. Benefitting from the efficient photosensitization ability of PB and the high PB-loading capacity of GO, the developed sensor allowed determination of 0.001 to 100 nM lysozyme with a limit of detection of about 0.14 pM. The relative standard deviation (RSD) for five independent electrodes with 1 nM lysozyme was 3.1%, indicating satisfactory reproducibility. The sensor also showed excellent selectivity toward lysozyme in the presence of interfering substances and was applied to the determination of lysozyme in urine samples with recoveries ranging from 91 to 101%. The on-line assembly of photosensitizer technique opens a new way for amplified electrosensing of biomolecules. Graphical abstract An on-line assembly of photosensitizers and DNA on electrode was developed using graphene oxide a cartridge and the photocatalytic electrosensor can be used for label-free detection of lysozyme as low as 1 pM.
一种基于超灵敏 O 的电化学适体传感器，通过使用氧化石墨烯 (GO) 作为试剂盒在线组装光催化剂来实现。在存在目标蛋白溶菌酶的情况下，溶菌酶与适体的相互作用导致 dsDNA 解离，并将适体-溶菌酶复合物释放到溶液中，而 DNA-c 保留在电极上；然后，由于 GO 可以同时吸附 DNA-c 和 PB 分子，光敏剂 phloxine B (PB) 被组装在电极上。在绿光 LED 的照射下，通过 PB 分子的光催化作用产生 O，然后将 DNA-c 切断，导致阻抗信号显著降低，与溶菌酶浓度的对数呈线性响应。得益于 PB 的高效光敏化能力和 GO 的高 PB 负载能力，开发的传感器允许在 0.001 至 100 nM 溶菌酶范围内进行检测，检测限约为 0.14 pM。具有 1 nM 溶菌酶的五个独立电极的相对标准偏差 (RSD) 为 3.1%，表明具有良好的重现性。该传感器在存在干扰物质的情况下对溶菌酶也表现出优异的选择性，并应用于尿液样品中溶菌酶的测定，回收率在 91%至 101%之间。在线组装光催化剂技术为生物分子的放大电化学传感开辟了新途径。
