3D-Printed Flow Cells for Aptamer-Based Impedimetric Detection of E. coli Crooks Strain

Abstract

Electrochemical spectroscopy enables rapid, sensitive, and label-free analyte detection without the need of extensive and laborious labeling procedures and sample preparation. In addition, with the emergence of commercially available screen-printed electrodes (SPEs), a valuable, disposable alternative to costly bulk electrodes for electrochemical (bio-)sensor applications was established in recent years. However, applications with bare SPEs are limited and many applications demand additional/supporting structures or flow cells. Here, high-resolution 3D printing technology presents an ideal tool for the rapid and flexible fabrication of tailor-made, experiment-specific systems. In this work, flow cells for SPE-based electrochemical (bio-)sensor applications were designed and 3D printed. The successful implementation was demonstrated in an aptamer-based impedimetric biosensor approach for the detection of Escherichia coli (E. coli) Crooks strain as a proof of concept. Moreover, further developments towards a 3D-printed microfluidic flow cell with an integrated micromixer also illustrate the great potential of high-resolution 3D printing technology to enable homogeneous mixing of reagents or sample solutions in (bio-)sensor applications.

3D Printing Technologies in Biosensors Production: Recent Developments

“…Material jetting can rely on its ability to print different objects in terms of mechanical properties with high resolution, even though it has its own limitation regarding printing time and accessibility [80,81]. In recent years, material jetting technology has been adopted to integrate 3D-printed microfluidics with biosensors, achieving high resolution (range of tens of microns), resulting in surface roughness of the printed device, its deformation, and resistance to harsh conditions [52][53][54][55]. Microfluidics, in fact, refers to the applied science of high-precision handling of fluids that are geometrically forced into networks of small channels, usually with micro-meter scale dimensions.…”

3D-printed microfluidics integrated with optical nanostructured porous aptasensors for protein detection

“…To date, there are only a handful of reports that combine 3D-printed microfluidics with aptasensors [19][20][21], and herein, we present for the first time the integration of a 3D-printed microfluidic device with a generic label-free optical porous silicon (PSi) aptasensor. The nanostructured PSi scaffold is used as the optical transducer, and binding of the target analyte to surface-immobilized aptamers, used as capture probes, is detected in real time by monitoring reflectivity changes of the PSi [22][23][24][25][26][27].…”

Label-Free Electrochemical Sensor for Rapid Bacterial Pathogen Detection Using Vancomycin-Modified Highly Branched Polymers

“…Electrochemical impedance spectroscopy (EIS) is a label-free detection method which has been applied for various different types of targets ranging from entire bacteria detection with immobilized antibodies, over nucleic acid targets to proteins and small molecules [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. We have previously developed in the Bachmann group EIS biosensors for the detection of the mecA gene and genomic DNA of methicillin-resistant S. aureus (MRSA), the New Delhi Metallo-beta-lactamase (NDM) carbapenem-resistance gene and for bacterial 16S ribosomal RNA for bacterial species identification [ 19 , 20 , 21 , 22 ].…”