Electrochemical aptasensor with signal amplification strategy of covalent organic framework-derived carbon material for ultrasensitive determination of carbendazim
Rong Zhang, Yanbo Zeng, Mengna Hu, Jian Zhang, Yiwen Yang, Haiqing Liu, Longhua Guo, Lei Li
Abstract
The inadequate conductivity inherent in some covalent organic frameworks (COFs) presents a challenge for their practical use in electrochemical sensors. To enhance the electrical conductivity of COFs, a high-temperature carbonization process can be employed to carbonize COFs in an inert atmosphere, resulting in the production of COF-derived porous carbon materials. In this study, a highly conductive COF-derived carbon material (COF-T 800 ) was obtained through the calcination of a COF known as TPB-DMTP-COF. Cyclic voltammetry (CV) current responses of the TPB-DMTP-COF electrode, when exposed to [Fe(CN) 6 ] 3−/4− , were found to be lower compared to those of a bare glassy carbon electrode (GCE). However, after the carbonization of TPB-DMTP-COF, the COF-T 800 electrode exhibited significantly higher current responses than bare GCE. The oxidation current response of COF-T 800 /GCE in [Fe(CN) 6 ] 3−/4− was 3.3 times higher than that of TPB-DMTP-COF, demonstrating superior conductivity for this carbonized material. Subsequently, COF-T 800 was employed as an electrochemical aptasensor substrate for signal amplification. This aptasensor had ultrasensitive determination of carbendazim (CBZ) with a linear response from 1.0 × 10 −12 to 1.0 × 10 −7 M. The detection limit of CBZ was 4.0 × 10 −13 M. This aptasensor demonstrated high selectivity and applicability for CBZ. The COF-T 800 -based electrochemical aptasensor was utilized for detecting CBZ in actual samples with success.