Smartphone-assisted Portable 3D Printed Platform for H₂O₂ Sensing using Chemiluminescence method

Detecting hydrogen peroxide (H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) is crucial in various sectors, including food analysis, environmental monitoring, and biomedical diagnostics. Portable chemiluminescence (CL) sensors offer an efficient solution for on-site H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> detection. This study introduces a low-cost, portable chemiluminescence sensor for H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> detection, developed using 3D printing technology. The sensing mechanism is based on a reaction involving luminol as the chemiluminescent agent and cobalt (II) ion complexes as catalysts. The system operates with microliter volumes of luminol, cobalt hexahydrate, and H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, and the reaction, lasting around 1.5 seconds, is recorded using a smartphone camera. The device was optimized and exhibited a linear response to H<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> concentrations in the range of 0.2 to 0.9 mM, with a coefficient of correlation of R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 0.92. The detection limit was determined to be as low as 0.10 mM. This method offers numerous advantages, utilizing a smartphone as the sensing device, including high sensitivity, excellent selectivity, simplicity, rapid response, and cost-effectiveness. The device has potential for broad application in POC diagnostics, and future work will explore its use for the detection of multiple bio-analytes.