Versatile MWCNT-COOH/PEDOT:PSS/Ru composite film used as sensing platform for high-efficiency detection of rutin

As a natural flavonoid glycoside, rutin has been made into many medical products due to its unique pharmacological activity. However, excessive intake of rutin is harmful to health. Therefore, developing a new sensing technique to achieve highly sensitive, rapid and on-site detection of rutin is of great significance to ensure food and medicine safety. Herein, an electrochemical sensing platform was proposed based on the nanocomposite of functionalized multi-wall carbon nanotubes/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/Ru nanoparticles (MWCNT-COOH/PEDOT:PSS/Ru) for rutin detection. The characterization techniques reveal that MWCNT-COOH and PEDOT:PSS crossed together forming a 3D interconnecting structure with plenty of areolations and high specific surface area, and Ru nanoparticles uniformly dispersed on the surface of MWCNT-COOH/PEDOT:PSS. Moreover, due to the good film reforming property of PEDOT:PSS, the as-obtained MWCNT-COOH/PEDOT:PSS/Ru composite shows special surface appearance as flexible free-standing film, which can be freely cut and used as sensing platform directly. Electrochemical experiments confirmed that MWCNT-COOH/PEDOT:PSS/Ru composite film performed satisfactory sensing properties toward rutin detection with wide linear ranges of 0.01 ∼ 0.7 μM and 0.7 ∼ 50 μM, low detection limit of 6.1 nM and high sensitivity of 79.43 μA μM −1 cm −2 . Besides, the composite sensing platform also exhibits high selectivity, reproducibility, and stability. During actual sample testing, the sensing platform was successfully applied for rutin detection in rutin pharmaceutical tablets and black buckwheat tea, showing promising application prospects in rapid, convenient, and high-efficiency on-site test.