ZIF67-derived porous carbon-reinforced electrospun nanofiber as an extractive phase for on-chip micro-solid-phase extraction of antifungals from biological fluids prior to liquid chromatography tandem mass spectrometry.

With a view to improving applicability as a sorbent while overcoming the challenges associated with its powdery nature, cobalt-doped zeolitic imidazolate framework (ZIF 67)-derived nanoporous carbon (Co-NPC) was employed as an additive in nanofiber through the process of electrospinning. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) surface area analysis were used to characterize the resulting nanocomposite. A microfluidic chip device with four layers, including two layers entailing spiral channels, was designed and employed to assess the analytical performance of the fabricated Co-NPC-reinforced electrospun composite. To do so, a folded piece of electrospun composite was sandwiched between two layers with spiral channels. Therefore, both sides of the folded composite acted as a sorptive phase to extract antifungal drugs as target analytes. The significant factors affecting the efficiency of the extraction process were investigated and optimized. Subsequently, the technique was verified through the utilization of liquid chromatography-tandem mass spectrometry (LC-MS/MS) by employing optimal parameters. The optimal conditions were applied to evaluate the figures of merit. A linear range was obtained for antifungal drugs within the range 0.25-200.0 ng ml with an R value of ≥ 0.9914. The method demonstrated detection limits ranging between 0.08 and 0.40 ng ml. The intra-day and inter-day precisions were less than 6.9%. Relative recoveries exhibited variations between 91.4-106.8%, 95.9-103.6%, and 96.4-109.3% for ketoconazole, clotrimazole, and miconazole, respectively. The proposed approach yielded satisfactory results, demonstrating its efficiency.