All-inorganic perovskite quantum dots CsPbX3 (Br/I) for highly sensitive and selective detection of explosive picric acid

As a new family of fluorescent materials, all inorganic perovskite quantum dots (PQDs) CsPbX 3 (Cl, Br, I) have attracted rising attention due to their intrinsic optical superiorities and potential applications in various fields. This work takes advantage of the bright fluorescence of PQDs and the strong electrophilic properties of picric acid (PA) to construct an analytical method for sensitive and selective discrimination of PA against other nitroaromatic explosives, and the limit of detection is as low as 0.8 nM. The quenching mechanism was elucidated as the formation of electrostatic complex and the electron transfer between PA and PQDs. To facilitate visual and on-site detection, the CsPbBr 3 PQDs were printed onto microfiltration membrane by inkjet printing to fabricate test papers for rapid and on-site detections of explosive and pollutant PA, showing a great research prospect in the detection of ultratrace PA at different sites.