From glow-sticks to sensors: Single-electrode electrochemical detection for paper-based devices

Abstract

With the goal of creating a multipurpose platform for electrogenerated luminescence, a single electrode electrochemical system was designed, developed, and validated. Glow sticks were used as the source of the luminophore, which was used as the optical reporter for the biosensor. A smartphone was used as the detector to quantify the electrochemiluminescence emissions. A disposable paper-based device was designed and used as a two-compartment electrochemical reaction cell, affording the possibility to individually optimize the sensing and detection reactions. This sensor assembly was tested under different conditions, showing acceptable performance both in the determination of hydrogen peroxide concentrations, to evaluate rancidity markers in edible oil samples, and to quantify the glucose concentration in soft drinks. The analytical performance of the single electrode, electrochemiluminescent device showed a limit of detection for hydrogen peroxide of 1.02 µM, with a working range between 0.4 µM and 150 mM. The proposed approach represents the first example of a system that combines paperbased devices, single electrode electrochemistry, electrochemiluminescence, and smartphone image sensing. As such, it not only provides a convenient platform for the development of a variety of analytical applications but also broaden the versatility of ePADs.