Hierarchical Polyacrylonitrile-Derived Nitrogen Self-Doped 3D Carbon Superstructures Enabling Electrochemical Detection of Calcium Channel Blocker Nimodipine in Real Human Blood Serum

Three-dimensional (3D) flower-like hierarchical carbon superstructures (CSs) have attracted significant attention for electrochemical sensor application due to their high specific surface area, more exposed active sites, and fast ion transport. Despite these advantages, finding a controllable method to fabricate porous carbons with distinctive morphologies has been challenging. Herein, we report a facile and tunable technique for the one-step synthesis of polyacrylonitrile (PAN) particles with different superstructures (peony flower-, rose petal-, oak leaf-, and jasmine petal-like shapes) controlled using different solvents [acetone (ACE), isopropyl alcohol (IPA), methanol (MeOH), and toluene (TOL)]. The obtained uniform PAN superstructures are altered into 3D hierarchical porous CSs via high-temperature gas treatment while preserving the original shapes of the PAN superstructures. For the first time, CSs (namely, CS-ACE, CS-IPA, CS-MeOH, and CS-TOL) were employed as an electrode material to investigate the electrochemical sensing of nimodipine (NMD) and were effectively compared with the sensing response attained in the modified electrode by PAN superstructure (namely, PS-ACE, PS-IPA, PS-MeOH, and PS-TOL). Interestingly, the electrochemical outcomes illustrate that the CS-ACE-modified electrode showed a better electrochemical activity toward NMD (limit of detection: 0.015 mu M, linear range: 0.1 to 390 mu M, and sensitivity: 9.63 mu A mu M-1 cm(-2)) than other modified electrodes. Finally, this study achieved satisfactory recovery results in real human blood serum samples for determining NMD.

Automated summary

A facile and tunable technique was developed to synthesize polyacrylonitrile (PAN) particles with different superstructures, which were transformed into 3D hierarchical porous carbon superstructures (CSs) with enhanced electrochemical activity for the sensing of nimodipine. Among the different modified electrodes, the CS-ACE-modified electrode exhibited the best electrochemical performance towards NMD, with a lower detection limit and higher sensitivity. Recovery results in real human blood serum samples also showed satisfactory performance for NMD determination.