Metal Microwires Functionalized with Cell-Imprinted Polymer for Capturing Bacteria in Water

Abstract

Molecularly imprinted polymers (MIPs) and cellimprinter polymers (CIPs) have emerged as synthetic recognition elements in biomimetic sensors. In this paper, we have conducted a parametric study to optimize a bulk polymerization methodology for uniform functionalization of stainless steel microwires (MWs) with CIPs comprising single to fourplex combinations of functional monomers (FMs). MWs are widely used in biosensors, and their functionalization with single-FM MIPs has been demonstrated. Complex MIPs comprising multiple FMs have shown enhanced selectivity toward microorganisms, but their coating on MWs has yet to be shown. Moreover, imprinting microorganisms into these coatings has not been reported. In our studies, solvent, FM, crosslinker-to-FM ratio, polymerization temperature, and time were found to significantly influence the thickness and uniformity of CIP coatings on MWs. Reproducible CIP coatings with a thickness of 2.2 ± 0.4 μm, imprinted with E. coli OP50 as the template, were achieved. E. coli rebinding assays demonstrated a 76 ± 10% capture efficiency in a suspension with an initial bacteria count of 10 4 CFU/mL, using a 3 cm long CIP-MW with an optimized fourplex CIP composition, while the capture efficiency obtained by using a single-monomer CIP composition was 30 ± 5%. Our results indicated a higher binding capacity of fourplex CIP-MWs to target bacteria, while nonsignificant binding was obtained using single-monomer CIP-MWs. The addition of N-vinylpyrrolidone significantly increased the binding performance due to its hydrophobic−hydrophilic functional groups interacting with counterparts on the surface of bacterial cells. The developed CIP-MWs can be integrated with microfluidic sensing systems as low-cost and stable working electrodes for future transduction of CIP-target binding events to an electrical read-out in CIP-based electrochemical biomimetic sensors.

Imprinting of nanoparticles in thin films: Quo Vadis?

“…Specically, they created cell-imprinted polymers (CIPs) on stainless steel microwires through chemical bonding between the functional monomers on the cell and the surface functional groups, and demonstrated that the interaction between the analyte and the surface is crucial for the rebinding capacity. 89 In the last decade, few interesting reviews have been published and focused on the recent development in the imprinting of large bioentities. Most of them highlighted new applications and summarized the recent imprinting strategies that have developed in recent times.…”

“…Specifically, they created cell-imprinted polymers (CIPs) on stainless steel microwires through chemical bonding between the functional monomers on the cell and the surface functional groups, and demonstrated that the interaction between the analyte and the surface is crucial for the rebinding capacity. 89 …”

Microfluidic Sensor Based on Cell-Imprinted Polymer-Coated Microwires for Conductometric Detection of Bacteria in Water

“…CIP pre-polymers were prepared by dissolving MAA (180 µL), AAM (21 mg), VP (4.2 µL), MMA (5.2 µL), EGDMA (570 µL), and AIBN (30 mg) in acetonitrile (2.2 mL). These quantities were optimized previously in a design of experiment exercise, leading to form a uniform and stable CIP coating with a thickness of 2.2 ± 0.4 µm on MWs [31]. The solution was ultrasonicated for 2 min in order to remove the dissolved gases.…”

“…CIPs synthesized by copolymers of methacrylic acid (MAA), acrylamide (AAM), methyl methacrylate (MMA), and N-vinylpyrrolidone (VP) have demonstrated enhanced selectivity toward biological templates by providing additional side chains during non-covalent imprinting [25,26,28,29]. We used this composition in previous works and generated microspheres with CIP shells [30] and CIP-coated microwires (called CIP-MWs) [31] that could bind to E. coli with high efficiency.…”