Direct Environmental Lead Detection by Photoluminescent Perovskite Formation with Nanogram Sensitivity

Abstract

Although the global ban on leaded gasoline has markedly reduced lead poisoning, many other environmental sources of lead exposure, such as paint, pipes, mines, and recycling sites remain. Existing methods to identify these sources are either costly or unreliable. We report here a new, sensitive, and inexpensive lead detection method that relies on the formation of a perovskite semiconductor. The method only requires spraying the material of interest with methylammonium bromide and observing whether photoluminesence occurs under UV light to indicate the presence of lead. The method detects as little as 1.0 ng/mm 2 of lead by the naked eye and 50 pg/mm 2 using a digital photo camera. We exposed more than 50 different materials to our reagent and found no false negatives or false positives. The method readily detects lead in soil, paint, glazing, cables, glass, plastics, and dust and could be widely used for testing the environment and preventing lead poisoning.

Photoluminescent detection of lead dust in gunshot residue

“…Moreover, we showed that this perovskite-based lead test is at least 1000 times more sensitive compared to state-of-the-art rhodizonate tests under laboratory conditions. [28] Unexpectedly, despite the notoriously problematic stability of perovskites, we detected lead in objects such as paints, waterpipes, dust, glass, and plastic, demonstrating that testing in real-world environments and conditions is feasible in a robust and reliable manner.…”

“…We recently exploited the versatile chemistry of lead and the bright photoluminescence (PL) of lead halide perovskites to develop a lead testing method based on perovskite formation. [28][29][30][31] In short, direct application of a reagent containing perovskite precursors (e.g. methylammonium halides) readily reacts with lead to form a lead halide perovskite semiconductor.…”

Lead-based paint detection using perovskite fluorescence and X-ray fluorescence

“…The present study evaluates a new kit marketed by the Dutch start-up Lumetallix that sprung out of research on the properties of Pb-halide perovskite to improve solar panels (Stranks and Snaith, 2015). The method was optimized for visual detection to produce an intense green fluorescence using methylammonium bromide (CH 3 NH 3 Br) in isopropanol in the presence of Pb regardless of its oxidation state (Helmbrecht et al, 2023). The Lumetallix reagent directly converts Pb into a light-emitting perovskite in a wide selection of specimens ranging from plastics and paints, to glazing and glass.…”