This paper describes the first approach at combining paper microfluidics with electrochemiluminescent (ECL) detection. Inkjet printing is used to produce paper microfluidic substrates which are combined with screen-printed electrodes (SPEs) to create simple, cheap, disposable sensors which can be read without a traditional photodetector. The sensing mechanism is based on the orange luminescence due to the ECL reaction of tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)_(3)~(2+)) with certain analytes. Using a conventional photodetector, 2-(dibutylamino)-ethanol (DBAE) and nicotinamide adenine dinucleotide (NADH) could be detected to levels of 0.9 (mu)M and 72 (mu)M, respectively. Significantly, a mobile camera phone can also be used to detect the luminescence from the sensors. By analyzing the red pixel intensity in digital images of the ECL emission, a calibration curve was constructed demonstrating that DBAE could be detected to levels of 250 (mu)M using the phone.
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