# Molecularly Imprinted Polymers as Biomimetic Test Zones in Paper-Based Nucleic Acid Assays—Comparing Vertical and Lateral Flow Formats

## TL;DR

This paper compares two paper-based nucleic acid test formats using synthetic receptors to detect Escherichia coli, showing their speed and sensitivity differences.

## Contribution

The study introduces biotin-specific molecularly imprinted polymers as stable synthetic receptors in paper-based nucleic acid assays.

## Key findings

- NAVF provided a 3-minute visual readout with a limit of detection of 1.00 × 10−2 ng mL−1.
- NALF achieved a visual limit of detection of 3.17 × 10−2 ng mL−1 with an assay time of less than 15 minutes.
- Biotin-MIPs demonstrated versatility for rapid, low-cost nucleic acid assays with format-specific advantages.

## Abstract

The development of rapid and sensitive point-of-care nucleic acid tests benefits from robust synthetic recognition elements. Here, a biotin-specific molecularly imprinted polymer (MIP) was synthesized using an optimized protocol and integrated as a biomimetic test zone into two paper-based formats: nucleic acid vertical flow (NAVF) and nucleic acid lateral flow (NALF). Both platforms were evaluated for the detection of double-tagged PCR amplicons from Escherichia coli. NAVF enabled a 3 min visual readout with an LOD of 1.00 × 10−2 ng mL−1. NALF provided a total assay time of <15 min and achieved a visual LOD of 3.17 × 10−2 ng mL−1. Overall, the results demonstrate the versatility of biotin-MIPs as stable synthetic receptors for rapid, low-cost paper-based nucleic acid assays, with NAVF prioritizing speed and design flexibility and NALF prioritizing higher analytical sensitivity.