Multiplex strategy electrochemical platform based on self-assembly dual-site DNA tetrahedral scaffold for one-step detection of diazinon and profenofos

In the work, based on self-assembly dual-site DNA tetrahedral scaffold (DTS), thionine (Thi), and 6-(Ferrocenyl) hexanethiol (Fc6S), a multiplex strategy electrochemical platform was fabricated for the simultaneous detection of profenofos (PFF) and diazinon (DZN). Thi and Fc6S were used to label aptamers for the synthesis of probes respectively. Notably, Thi and Fc6S engendered recognizable DPV peaks at different potentials to achieve simultaneous detection of PFF and DZN. In addition to increasing the conductivity of the electrode, the combination of carboxylic acid functionalized multi-walled carbon nanotubes and ferroferric oxide nanoparticles could also increase its higher specific surface area of the electrode interface to adsorb more DTS. Because of the mechanical rigidity of the DTS, the DTS could keep a complementary chain upright and provide more binding sites for aptamers, the binding efficiency between the complementary chain and 2 binding aptamers could be improved. Comparing the aptasensors performance of single-strand DNA with that of the DTS with complementary strands, the benefits of the DTS were highlighted in this system. Under optimal conditions, the detection limits of PFF and DZN were both 3.33 pg/mL and the detection ranges were both 1.00 x 101-1.00 x 107 pg/mL. Meanwhile, the recoveries of PFF and DZN were 87.15%-117.34% and 91.20%-114.19%, respectively. The aptasensor could

Automated summary

A multiplex strategy electrochemical platform was developed for the simultaneous detection of profenofos (PFF) and diazinon (DZN) using a self-assembly dual-site DNA tetrahedral scaffold (DTS). Thionine (Thi) and 6-(Ferrocenyl) hexanethiol (Fc6S) were used to label aptamers for the synthesis of probes. The combination of carboxylic acid functionalized multi-walled carbon nanotubes and ferroferric oxide nanoparticles improved the conductivity and specific surface area of the electrode.