The chemiluminescence paper-based analytical device for lead measurement in gasoline

This study developed a paper-based analytical device with a chemiluminescence detection method (PAD-CL) to determine lead cations (Pb²⁺) in a gasoline sample. The paper substrate was modified with NiO hollow microspheres (NiO HMs) to catalyze the luminol-O₂ CL reaction. The developed PAD-CL was embedded in a homemade holder to facilitate CL reaction monitoring using a luminometer. The Pb²⁺ suppresses the CL reaction, and this signal was used to draw a calibration curve. The effective parameters on the CL performance, such as drying time for NiO and Pb²⁺ solutions, drop volume of solutions, and concentrations of NaOH, luminol, and NiO HMs, were investigated. At the optimum conditions, the calibration curve for Pb²⁺ was linear in the range of 8.00 × 10^-9 to 8.00 × 10^-7 mol L^-1 (R² = 0.99). A limit of detection (3S) of 1.29 × 10^-9 mol L^-1 was obtained. The acceptable relative standard deviation (RSD) was obtained for the proposed CL method (7.01 %, n = 5) for a 2.00 × 10^-8 mol L^-1 Pb²⁺ solution. Application to gasoline samples demonstrated satisfactory selectivity and accuracy. The study also examined the CL reaction mechanism. This novel PAD-CL approach for Pb²⁺ measurement in gasoline is environmentally significant. Its advantages include minimal reagent use and the absence of external oxidants. The paper substrate enhances ease of use, storage, and transport, as samples and reagents flow through the paper via capillary action and gravity. Additionally, paper's availability, affordability, renewability, and environmental benefits, such as disposability by incineration, support mass production and sustainability.