Electrochemiluminescence detection in microfluidic cloth-based analytical devices

This work describes the first approach at combining microfluidic cloth-based analytical devices (μCADs) with electrochemiluminescence (ECL) detection. Wax screen-printing is employed to make cloth-based microfluidic chambers which are patterned with carbon screen-printed electrodes (SPEs) to create truly disposable, simple, inexpensive sensors which can be read with a low-cost, portable charge coupled device (CCD) imaging sensing system. And, the two most commonly used ECL systems of tris(2,2ʹ-bipyridyl)ruthenium(II)/tri-n-propylamine (Ru(bpy)32+/TPA) and 3-aminophthalhydrazide/hydrogen peroxide (luminol/H2O2) are applied to demonstrate the quantitative ability of the ECL μCADs. In this study, the proposed devices have successfully fulfilled the determination of TPA with a linear range from 2.5 to 2500 μM with a detection limit of 1.265 μM. In addition, the detection of H2O2 can be performed in the linear range of 0.05-2.0 mM, with a detection limit of 0.027 mM. It has been shown that the ECL emission on the wax-patterned cloth device has an acceptable sensitivity, stability and reproducibility. Finally, the applicability of cloth-based ECL is demonstrated for determination of glucose in phosphate buffer solution (PBS) and artificial urine (AU) samples, with the detection limits of 0.032 mM and 0.038 mM, respectively. It can be foreseen, therefore, that μCADs with ECL detection could provide a new sensing platform for point-of-care testing, public health, food safety detection and environmental monitoring in remote regions, developing or developed countries.