Lateral flow assays are widely used for rapid diagnostics at the point of care. However, their dependence on biological receptors limits their stability, scalability, and cost-effectiveness. This work demonstrates the use of biotin-specific molecularly imprinted polymers (biotin-MIPs) as synthetic recognition elements in nucleic acid lateral flow (NALF) assays. The biotin-MIPs were synthesized, structurally characterized, and integrated into the nitrocellulose membrane as a test line. Their selective binding affinity was first validated using biotinylated horseradish peroxidase as a model analyte. The platform was then evaluated for the detection of double-tagged PCR amplicons from Escherichia coli labeled with biotin and digoxigenin, achieving a visual detection limit of 2 ng mL-1 and a limit of detection of 1.8 ng mL-1, with no detectable signal in negative controls. Clinical feasibility was further assessed retrospectively using swab specimens collected during routine third-trimester screening (35-37 weeks of gestation) for Group B Streptococcus, a major cause of neonatal sepsis. In this proof-of-concept study, the MIP-based NALF assay showed complete qualitative agreement with the qPCR reference classification and the gold standard microbiological culture, demonstrating the compatibility of this approach with battery-operated portable PCR amplification. Unlike biological receptors, MIPs offer robustness, long-term stability at room temperature, and animal-free scalable production. These features position the MIP-based NALF platform as a cost-effective alternative to antibody-based tests and a promising foundation for next-generation lateral flow diagnostics for the detection of communicable diseases at the point of care.
Marfà et al. (Tue,) studied this question.