3D-printed bioanalytical devices

Abstract

While 3D printing technologies first appeared in the 1980s, prohibitive costs, limited materials, and the relatively small number of commercially available printers confined applications mainly to prototyping for manufacturing purposes. As technologies, printer cost, materials, and accessibility continue to improve, 3D printing has found widespread implementation in research and development in many disciplines due to ease-of-use and relatively fast design-to-object workflow. Several 3D printing techniques have been used to prepare devices such as milli- and microfluidic flow cells for analyses of cells and biomolecules as well as interfaces that enable bioanalytical measurements using cellphones. This review focuses on preparation and applications of 3D-printed bioanalytical devices.

Figure 1

Illustrated schematic of an FDM 3D printer. A) Thermoplastic filament is fed through a heated nozzle onto a moving platform. A gantry system controls X and Y movements of the extruder assembly. B) Components of the extruder assembly are depicted. Drive gear and motor used to deliver filament to heated nozzle.

Figure 2

Illustrated schematic of a laser-based SLA 3D printer.

Figure 3

Images of a 3D-printed fluidic device for determination of adenosine triphosphate released by erythrocytes. A) The design for the fluidic device (bottom) was based on a 96-well plate (top) so that a commercial plate reader could be used for measurements. B) Membrane inserts (top) were placed in the printed wells (bottom, leftmost channel). C) Fluidic channels were connected to fluid delivery system (pump) via commercially available fittings and tubing. Adapted from Reference with permission from the Royal Society of Chemistry.

Figure 4

FDM-printed devices that enable gravity-flow reagent and washing buffer delivery for ECL-based immunoassays. (A) A screen-printed electrode array is affixed to the bottom of a 3D-printed reagent delivery system. Serum sample, antibody (AB₂)-labeled silica nanoparticles (Si-NP) filled with ECL dye Ru(bpy)₃²⁺, and ECL coreactant tri-n-propylamine are stored in reservoirs. Delivery of reagents to the open-top channel is accomplished by removing reservoir inserts. B) 3D model (left) and photograph of wash reservoir module showing freely moving lever to change between wash and load positions. A lever is used to adjust the position of the array so that reagents or washing buffer can be held on the electrode array surface for incubation or flowed over for washing. Reprinted from Reference with permission from Elsevier.

Figure 5

Cellphone-based colorimetric assay for peanut allergen conducted using a 3D-printed platform for sample handling. (a) A photograph of 3D-printed platform is connected to a smartphone for sample measurement. (b) An opto-mechanical attachment (dimensions: ~22 mm × 67 mm × 75 mm) equipped with light-emitting diodes enables colorimetric measurements by the cellphone camera. (c) A schematic diagram of the interface, depicting components of the opto-mechanical attachment. Reproduced from Reference with permission of The Royal Society of Chemistry.