Lipopolysaccharide-templated biomimetic molecularly imprinted polymer (MIP) surfaces for high-affinity bacterial capture

The development of synthetic materials capable of efficiently capturing bacteria is essential for applications in biosensors, environmental monitoring and pathogen detection. However, traditional bacteria-imprinted polymers (BIPs), which demand whole bacterial cells as templates, face critical limitations in biosafety, scalability, and standardization. To overcome these challenges, we present a new class of synthetic bacterial recognition materials that eliminate the need for whole bacterial templates. This is achieved via a novel imprinting strategy that combines photolithographic surface imprinting with molecular imprinting. A PDMS-based master stamp containing a high-density array of photolithographically defined biomimetic Escherichia coli microstructures was developed and subsequently chemically functionalized with E. coli surface components (lipopolysaccharides (LPSs)). Comprehensive characterization using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), contact angle, and Zeta potential measurements confirmed that the synthetic microstructures closely mimic both the shape and surface chemistry of E. coli . The functionalized stamp enables the simultaneous formation of shape-complementary cavities and LPS-derived chemical patterns (molecular fingerprints of E. coli ) on a polyurethane substrate in a single imprinting step. The resulting biomimetic molecularly imprinted polymers (MIPs) showed significantly enhanced bacterial capture performance (imprinting factor: 6.5), outperforming geometry-only and LPS-only imprinted surfaces. The results highlight the synergistic effect of combining physical and molecular recognition, establishing a scalable, whole-cell-templating-free strategy for fabricating high-affinity synthetic receptors.