Molecularly imprinted polymer-based sensors for forensic science: A review of the way forward for presumptive testing

Molecularly imprinted polymers (MIPs) offer stable, reusable, and specific synthetic recognition sites for chemical sensing. MIP-based drug sensors are promising tools for forensic biological-matrix drug screening before confirmatory analysis, but their translation into forensic practice is constrained less by peak analytical sensitivity than by explicit decision rules at the program screening cutoff, embedded quality control (QC), and traceable records compatible with chain-of-custody review. To evaluate this translation gap, we reviewed 114 studies published from 2015 to early 2026 and organized a standards-aligned framework with three boundary conditions (BCs). BC-I (matrix robustness) requires matrix-robust, interpretable signals in realistic specimens. BC-II (cutoff-centered decision rules) requires explicit decision rules at the program screening cutoff, optionally with a predefined Inconclusive Zone and prespecified follow-up actions. BC-III (lifecycle comparability) requires consistent decisions across lots, devices, operators and over time via embedded QC, lot-bridging, and version-controlled configuration. Using representative MIP platforms and drug-sensing case studies, we identify recurring gaps that hinder MIP deployment in forensic presumptive testing, including narrow matrix panels, incomplete raw-trace provenance, absent borderline handling, and limited lifecycle-comparability documentation. We believe that practical progress will often depend on adopting mature quality system practices, routine near-cutoff testing, and complete documentation to support traceable screening decisions.