title: 3D printed LED based on-capillary detector housing with integrated slit.
abstract: A 3D printed photometric detector body with integrated slit was fabricated to position a LED and photodiode either side of capillary tubing using a fused deposition modelling (FDM) printer. To make this approach suitable for capillaries down to 50 μm i.d. the dimension of the in-built slit is the critical element of the printed housing. The spatial orientation of the model for printing was found to significantly impact on the resolution of the structures and voids that can be printed. By designing a housing with a slit positioned in the XY plane in parallel with the print direction, the narrowest void (slit) that could be printed was 70 μm. The potential use of the 3D printed slit for photometric detection was characterised using tubing and capillary from 500 down to 50 μm i.d, demonstrating a linear response from 632 to 40 mAU. The effective pathlength and stray light varied from 383 to 22 μm and 3.8% - 50% for 500- 50 μm i.d tubing and capillary. The use of a V-shaped alignment feature allowed for easy and reliable positioning of the tubing inside the detector, as demonstrated by a RSD of 1.9% (n = 10) in peak height when repositioning the tubing between measurements using flow injection analysis (FIA). The performance of the 3D printed housing and 70 μm slit was benchmarked against a commercially available interface using the CE separation of Zn2+and Cu2+complexes with PAR. The limit of detection with the 3D printed slit was 6.8 and 4.5 μM and is 2.8 and 1.6 μM with the commercial interface.
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001, Australia.
authors.forename: Farhan
authors.initials: F
authors.lastname: Cecil
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001, Australia.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Medicine, University of Tasmania, Private Bag 75, Hobart 7001, Australia.
authors.forename: Rosanne M
authors.initials: RM
authors.lastname: Guijt
authors.affiliation: School of Engineering and ICT, University of Tasmania, Private Bag 75, Hobart 7001, Australia.
authors.forename: Alan
authors.initials: A
authors.lastname: Henderson
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001, Australia; ARC Centre of Excellence for Electromaterials Science, University of Tasmania, Private Bag 75, Hobart 7001, Tasmania, Australia.
authors.forename: Pavel N
authors.initials: PN
authors.lastname: Nesterenko
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001, Australia; ARC Centre of Excellence for Electromaterials Science, University of Tasmania, Private Bag 75, Hobart 7001, Tasmania, Australia.
authors.forename: Brett
authors.initials: B
authors.lastname: Paull
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001, Australia; ARC Centre of Excellence for Electromaterials Science, University of Tasmania, Private Bag 75, Hobart 7001, Tasmania, Australia.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Breadmore
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001, Australia. Electronic address: mirek.macka@utas.edu.au.
authors.forename: Mirek
authors.initials: M
authors.lastname: Macka
keywords: 3D printing; Capillary electrophoresis; Flow injection analysis; Fused deposition modelling; LED on-capillary detector; Light emitting diode