Two-photon stereolithography is used for rapid prototyping of submicrometre molecularly imprinted polymer-based 3D structures. The structures are evaluated as chemical sensing elements and their specific recognition properties for target molecules are confirmed. The 3D design capability is exploited and highlighted through the fabrication of an all-organic molecularly imprinted polymeric microelectromechanical sensor.
This work presents a polymeric centrifugal microfluidic platform for the rapid and sensitive identification of bacteria directly from urine, thus eliminating timeconsuming cultivation steps. This "Lab-on-a-Disc" platform utilizes the rotationally induced centrifugal field to efficiently capture bacteria directly from suspension within a glass-polymer hybrid chip. Once trapped in an array of small V-shaped structures, the bacteria are readily available for spectroscopic characterization, such as Raman spectroscopic fingerprinting, providing valuable information on the characteristics of the captured bacteria. Utilising fluorescence microscopy, quantification of the bacterial load has been achieved for concentrations above 2 Â 10 À7 cells ml À1 within a 4 ll sample. As a pilot application, we characterize urine samples from patients with urinary tract infections. Following minimal sample preparation, Raman spectra of the bacteria are recorded following centrifugal capture in stopped-flow sedimentation mode. Utilizing advanced analysis algorithms, including extended multiplicative scattering correction, high-quality Raman spectra of different pathogens, such as Escherichia coli or Enterococcus faecalis, are obtained from the analyzed patient samples. The whole procedure, including sample preparation, requires about 1 h to obtain a valuable result, marking a significant reduction in diagnosis time when compared to the 24 h and more typically required for standard microbiological methods. As this cost-efficient centrifugal cartridge can be operated using low-complexity, widely automated instrumentation, while providing valuable bacterial identification in urine samples in a greatly reduced time-period, our opto-microfluidic Lab-on-a-Disc device demonstrates great potential for nextgeneration patient diagnostics at the of point-of-care. V C 2015 AIP Publishing LLC.
We describe the synthesis of water-soluble molecularly imprinted polymer nanoparticles (MIP-NPs) as a new artificial host receptor for the recognition of adenosine monophosphate (AMP), used herein, as a model nucleotide. MIP-NPs were prepared by solid-phase synthesis on glass beads (GB) using, for the first time, immobilized Fe(III)chelate as an affinity ligand to orientate the AMP via its phosphate group. A polymerizable thymine monomer which can induce complementary base-pairing with the adenine moiety of the nucleotide was synthesized and incorporated in the polymerization mixture to constrain the AMP in a dualorientated configuration. The MIP-NPs were remarkably selective toward AMP as they did not bind other nucleotides, GMP, UMP, and CMP. This strategy of using the phosphate group of AMP as a hinge enables unhindered pairing of the nucleobase with its corresponding complementary base monomer and can be extended to the preparation of specific MIP receptors for other key nucleotides in aqueous conditions.
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