Signal switching electrochemical and fluorescence dual-mode sensing platform for carbendazim determination based on "two-in-one" magneto-fluorescent Cdots.

An innovative method for carbendazim (CBZ) detection was developed, consisting of an electrochemical-fluorescence dual-mode biosensor based on magneto-fluorescent composite M-CDs. M-CDs, as the fluorescent probe of this sensor, could combine the electrical signal-ferrocene to achieve the "signal switching" by specifically recognizing CBZ through aptamers, of which magnetic property was used to quickly separate from complex substrates without interference. The dual-mode sensor based on M-CDs demonstrated excellent linear responses in both electrochemical and fluorescence assays. It achieved detection ranges of 10 fg/mL - 300 ng/mL and 60 fg/mL - 100 ng/mL with detection limits (LODs) of 1.4 fg/mL and 2.3 fg/mL. The sensor exhibited exceptional detection performance, stability and anti-interference. In addition, the results of the sensor in actual samples were consistent with those of enzyme-linked immunosorbent assay (ELISA), which further demonstrated that the sensor could accurately trace detecting CBZ in real samples and had a certain application prospect.