Microfluidic paper device with on-site heating to produce reactive peroxide species for enhanced smartphone enabled...

Chemiluminescence signal amplification (CLSA) is of huge interest because of its sensitive detection in various applications such as food analysis, biomedical diagnosis and environmental monitoring. Due to this, there is a manifold attention to develop rapidly prototyped and miniaturized devices for CLSA. In this context, herein, a novel CLSA approach is demonstrated on a 3D printed microfluidic paper-based analytical device (μPADs), fabricated using Fused deposition modeling (FDM) printing technology. Influence of working temperature, ranging 30 °C-110 °C, on CL signal generation from well-established Luminol/Co⁺² - H₂O₂ reaction was analyzed using a screen-printed flexible heater onto the 3D printed reaction platform. A smartphone-based capturing/detection system provided the amenability for a point-of-care testing system. For the first time, strong and stable CLSA was found with about 255% ± 5% increase in its signal intensity without using any additional external enhancers. The on-site working temperature was directly in proportional to the intensity of CL signal generated from Luminol/Co⁺² - H₂O₂ reaction under optimum conditions, wherein the device had a wide linear range from 50 nM to 1 μM with a detection limit of 35 nM for H₂O₂ detection. The reliability of the developed amplification method was tested for practicability to detect the concentration of H₂O₂ in milk as real sample analysis. Overall, such CLSA mechanism in miniaturized μPADs will have strong potential for multiple CL based detection and monitoring application.