Fabrication of Analytical Paper Device Containing Seleno BODIPY for Fluorometric and Colorimetric Detection of Palladium II

Description:
Microfluidic paper-based analytical devices (uPADs) can be an alternative to conventional spectrometer apparatus since the paper is a low cost and low weight for on-site measurements. Visual detection is an excellent match to uPADs since paper can contain storage reactants. A colorimetric reaction can occur on the paper surface, and it can be measured through a photograph using a regular phone or camera. Hence, we propose a paper analytical device containing spot zones delimited by a wax barrier to confine a colorimetric/fluorometric reagent (seleno BODIPY. It was found that this compound reacts selectively with Pd2+ leading to very evident color change [1], allowing visual detection (Red value). Additionally, the resulting coordination compound exhibited high fluorescence under UV lamp. Palladium (Pd) is one of the most powerful components of the toolbox of preparative chemistry, being the cross-coupling one of the most ordinary employed in the preparation of a myriad of goods, including IFA’s. On the other hand, due to the high toxicity of Pd, its presence in any of the final products needs quantification. The colorimetric and fluorimetric selectivity of the fabricated sensor was tested through different cations, showing exclusive response to Pd2+, even when in the presence of other cations. Aiming for quantification applications, a calibration curve was constructed for both fluorometric (under UV) and colorimetric. A linear range (LR) from 56 to 700 umol L-1 with a detection limit (LD) of 46 umol L-1 for colorimetric detection was observed. Fluorimetricly, a LR from 14 to 980 umol L-1 with a LD of 16 umol L-1 was achieved. The constructed device showed excellent stability over 15 days, with the reaction giving the same R-value throughout this period. Real tests were performed to detect Pd2+ in medicines, such as acetaminophen, with good agreement with the added value. References 1. Cugnasca, Beatriz S., et al., Current Chemical Biology, 2021, 15, 3, 215-221.