Synthesis of hierarchical porous ZIF-8/3DCNTs composite sensor for ultrasensitive detection of DA and DFT studies

A hybrid nanocomposite of hierarchical porous zeolitic imidazolate framework-8 / three-dimensional carbon nanotubes (HP-ZIF-8/3DCNTs) has been successfully fabricated by constructing micelle by sodium dodecyl sulfate (SDS) and deep eutectic solvent (DES) aqueous solution to grow HP-ZIF-8 in situ on the 3DCNTs template. The electrochemical performance for detecting dopamine (DA) is greatly improved owing to the synergism of highly conductive CNTs and hierarchical porous ZIF-8. At the same time, the electrochemical reaction of DA on HP-ZIF-8/3DCNTs/GCE is an adsorption control process, and density function theory (DFT) calculation was performed to analysis the charge distribution and interaction force of DA and dopaminophenone in the material, forming a molecular complex with adsorption energy of -19.11 and - 25.21 kJ/mol(-1). In addition, the response current is linear when the DA content is 1.0 x 10(-7) to 1.0 x 10(-4) M, the LOD is 2.7 x 10(-8) M at S/N = 3. The electrode material has excellent selectivity, sterling reproducibility of 2.21% and satisfactory repeatability with a RSD of 1.96%, and splendid long-term stability with peak current maintained 96.03% of the initial value after 14 days. The results indicate that HP-ZIF-8/3DCNTs composite has broad application prospects in the field of electrochemical sensing, and its modification methods and theoretical concepts can potentially be applied to the research of other sensors.