3D printed UV/VIS detection systems constructed from transparent filaments and immobilised enzymes

Transparent materials for fused filament fabrication printers are widely available and may be useful for constructing 3D printed devices with applications in UV/VIS spectroscopy. In this study, colourless polylactic acid, HD Glass and T-Glase were evaluated as construction materials for biochemical sensors, which contain immobilised enzymes, for analysis by UV/VIS spectrophotometry. Experiments were conducted on both the native 3D print and after coating with XTC-3D®, a transparent epoxy resin used to improve optical transparency of 3D prints. A combination of HD Glass or T-Glase with XTC-3D®, gave the highest transparency, probably due to the similar refractive indices of these materials. Individual enzymes were immobilised within the 3D prints by coupling the enzymes to tosyl-activated magnetic beads and attracted to the print surface by magnets embedded in the 3D print. A transparent 3D printed device was demonstrated using enzymatic assays of lactose and glucose. This device can be configured to contain up to three separate reaction chambers and features a separate colorimetric analysis chamber. Further studies showed that enzyme assays performed in these 3D printed devices are reproducible, accurate and of comparable sensitivity to the same assays performed in polystyrene cuvettes.