A fully integrated and handheld electrochemiluminescence device for detection of dopamine in bio-samples

Electrochemiluminescence (ECL) is a powerful electroanalytical transduction technique in biosensing and clinic immunodiagnostics, however its practical applications for point-of-care testing (POCT) are rather limited because of the requirements of large sized electrochemical workstation for electrical stimulation and photomultiplier tube for light detection. Herein we report a fully integrated and handheld ECL device consisting of a flexible printed circuit board based electrochemical module, a silicon photomultiplier and a Bluetooth enabled smartphone with an Android application interface. The device together with an electrochemical cell and light-tight box has a dimension of 17 cm × 9 cm × 9 cm, thus being suitable for on-site detection and POCT. To demonstrate the performance and efficiency of this device, we implemented the detection of dopamine (DA), using the indium tin oxide glass electrode coated with antifouling silica nanoporous membrane as the working electrode for improving the sensing stability and sensitivity. A fast response to DA with a wide linear range of 5 nM ∼ 20 μM and an ultralow detection limit of 3.5 nM were obtained with the handheld ECL device. These attractive features allow the device to satisfy the basic requirements for POCT of DA in complex bio-samples, including urine and rat brain homogenate. This work provides a novel strategy for ECL based POCT, showing the potential of broad utility in resource-limited settings where there is a lack of medical facilities.