Recent Advances in Nano Sorbent Materials for Solid-Phase Microextraction in Forensic Drug Analysis: Design,...

Solid-phase microextraction (SPME) has evolved into a key sample preparation technique in forensic drug analysis due to its solvent-free operation, high sensitivity, and compatibility with complex matrices. This review critically evaluates recent advances (2018-2025) in SPME sorbent materials, with particular emphasis on their design, functionalization, and analytical performance. Advanced sorbents, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), molecularly imprinted polymers (MIPs), carbon nanotubes (CNTs), hydrophilic-lipophilic balance (HLB) materials, and polymeric ionic liquids (PILs), demonstrate significant improvements over conventional coatings such as polydimethylsiloxane (PDMS) and polyacrylate (PA). Reported enhancements include up to 24-fold higher adsorption capacity (SPME Arrow), 1.7-2245-fold increases in enrichment factors (COF-based sorbents), and LOD as low as ≤ 0.25-2 ng/mL in biological matrices. Recovery rates across advanced materials typically range from ∼77% to >100%, with hybrid and HLB-based systems achieving 81-120% and improved matrix tolerance. Additionally, CNT- and MOF-based sorbents exhibit high durability, maintaining performance over 50-300 extraction cycles, while MIP-based systems provide high selectivity with protein exclusion up to 98%. The review systematically correlates sorbent chemistry, fabrication strategies, and extraction mechanisms with analytical figures of merit, including sensitivity, linearity, and precision. By integrating these quantitative comparisons, this work highlights how rational sorbent design enhances extraction efficiency, reduces matrix effects, and improves reproducibility. The findings provide a comprehensive framework for selecting and developing next-generation SPME materials to support reliable, high-throughput, and legally defensible forensic drug analysis.