Portable electrochemiluminescent detection system with 3D printed materials and mobile phone detection

3D printing offers advantages and novel opportunities for the analytical chemistry laboratory. The method presented here used 3D printed materials as the substrates for electrochemiluminescent sensors and used 3D printing to construct a portable housing for the sensors that not only aligns the sensor to the detector but provides a light-tight environment for the luminescence measurement. This work evaluated four different 3D-printed plastics as substrate materials for sensors fabricated from stencil-printed carbon-ink electrodes (SPCE's). SPCE chips were fabricated that incorporated an electrochemical cell onto three different plastics printed via fused deposition modeling and a plastic printed using stereolithography printing. The chips were used to develop an ECL detection method with the luminophore tris(2,2'-bipyridyl)ruthenium(II) [ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup><mml:mrow><mml:mtext>Ru</mml:mtext> <mml:mo>(</mml:mo> <mml:mtext>bpy</mml:mtext> <mml:mo>)</mml:mo></mml:mrow> <mml:mn>3</mml:mn> <mml:mrow><mml:mn>2</mml:mn> <mml:mo>+</mml:mo></mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> ] and 2-(dibutylamino) ethanol (DBAE). The ECL reaction between <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup><mml:mrow><mml:mtext>Ru</mml:mtext> <mml:mo>(</mml:mo> <mml:mtext>bpy</mml:mtext> <mml:mo>)</mml:mo></mml:mrow> <mml:mn>3</mml:mn> <mml:mrow><mml:mn>2</mml:mn> <mml:mo>+</mml:mo></mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> and DBAE was used to optimize a chip-based ECL detection method for amine-containing species. The limits of detection ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mi>S</mml:mi> <mml:mrow><mml:mo>∕</mml:mo> <mml:mi>N</mml:mi></mml:mrow> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>3</mml:mn></mml:mrow> </mml:math> ) for DBAE on the four different substrates were similar, ranging from 3 - 4 μM. The method was applied to the detection of the biogenic amine spermidine. The method had a detection limit of ~130 μM for spermidine. With goals of accessibility and portability, the method also utilized a mobile phone detector, and portability was demonstrated with the use of a USB power supply to generate the voltage for the ECL reaction.