Surface-Imprinted Polymer Coupled with Diffraction Gratings for Low-Cost, Label-Free and Differential E. coli Detection

Biosensors, vol. 16, pp. 60

Abstract

Surface-imprinted polymer (SIP)-based biomimetic sensors are promising for direct whole-bacteria detection; however, the commonly used fabrication approach (micro-contact imprinting) often suffers from limited imprint density, heterogeneous template distribution, and poor reproducibility. Here, we introduce a photolithography-defined master stamp featuring E. coli mimics, enabling high-density, well-oriented cavity arrays (3 × 107 imprints/cm2). Crucially, the cavity arrangement is engineered such that the SIP layer functions simultaneously as the bioreceptor and as a diffraction grating, enabling label-free optical quantification by reflectance changes without additional transduction layers. Finite-difference time-domain (FDTD) simulations are used to model and visualize the optical response upon bacterial binding. Proof-of-concept experiments using a differential two-well configuration confirm concentration-dependent detection of E. coli in PBS, demonstrating a sensitive, low-cost, and scalable sensing concept that can be readily extended to other bacterial targets by redesigning the photolithographic master.

Authors 5

1. Dua Özsoylu Aachen Institute of Nano- and Biotechnologies (INB)

   FH Aachen

   Affiliation as printed

   Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Jülich, 52428 Jülich, Germany

2. Elke Börmann-El-Kholy Aachen Institute of Nano- and Biotechnologies (INB)

   FH Aachen

   Affiliation as printed

   Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Jülich, 52428 Jülich, Germany

3. Rabia N. Kaya Aachen Institute of Nano- and Biotechnologies (INB)

   FH Aachen

   Affiliation as printed

   Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Jülich, 52428 Jülich, Germany

4. Patrick Hermann Wagner

   KU Leuven

   Affiliation as printed

   Laboratory for Soft Matter and Biophysics, Department of Physics and Astronomy, KU Leuven, B-3001 Leuven, Belgium

5. Michael Josef Schöning Aachen Institute of Nano- and Biotechnologies (INB)

   Forschungszentrum Jülich · FH Aachen

   Affiliation as printed

   Institute of Biological Information Processing (IBI-3), Research Centre Jülich GmbH, 52425 Jülich, Germany

   Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Jülich, 52428 Jülich, Germany