On-Chip Electromembrane-Surrounded Solid-Phase Microextraction for Ultra-Trace Drug Analysis in Bone Marrow Aspirate

A microfluidic on-chip electromembrane-surrounded solid-phase microextraction (EM-SPME) method was developed for the sensitive and selective determination of tricyclic antidepressants (TCAs) in complex biological matrices. The device integrates a poly(3,4-ethylenedioxythiophene)–graphene oxide (PEDOT–GO) nanocomposite coating on a stainless-steel fiber, serving as both the acceptor electrode and extraction medium. A hollow membrane impregnated with a supported liquid membrane (SLM)encloses the fiber, enabling efficient electrokinetic migration of analytes from the donor to acceptor microchannel while minimizing matrix interferences. The PEDOT–GO nanocomposite, characterized by SEM, FT-IR, and zeta potential analyses, provided enhanced adsorption capacity through π–π interactions, hydrogen bonding, and electrostatic attraction, leading to improved extraction efficiency.
Six antidepressants—including amitriptyline, nortriptyline, imipramine, desipramine, maprotiline, and sertraline—were analyzed using GC–MS. The method exhibited limits of detection of 0.005–0.025 μg/L, linear ranges from 0.01–500 μg/L (imipramine and sertraline) to 1–250 μg/L (maprotiline), and relative standard deviations ≤ 8.4%. Recoveries in spiked biological fluids including bone marrow aspirate, plasma, and urine ranged from 93–105%, demonstrating excellent reproducibility and applicability to real-world matrices. Compared to conventional SPME approaches, the integrated electromembrane barrier significantly reduced carryover and matrix effects while maintaining high sensitivity.
This work introduces a versatile, miniaturized and high-performance platform for trace drug analysis, combining microfluidics, electromembrane extraction, and conductive polymer–nanomaterial coatings. The strategy is well suited for bioanalytical and forensic applications requiring exceptional sensitivity and selectivity in challenging biological matrices.