Preparation of a Cs4PbBr6 NCs@PCDs ratiometric fluorescent probe and detection of amoxicillin

Abstract

Water-stable Cs₄PbBr₆ nanocrystals (Cs₄PbBr₆ NCs) are combined with ultra-stable polymer carbon dots (PCDs) to create a double-emission detection system. This system was developed specifically for identifying amoxicillin (AMX) in aqueous environments. Experimental data revealed that the Cs₄PbBr₆ NCs displayed bright green luminescence under UV irradiation. The emission peak was observed at a wavelength of 519 nm, with a half-peak width of approximately 30 nm. Furthermore, the fluorescence persisted for over 48 hours after the Cs₄PbBr₆ NCs were dissolved in water. Additionally, the probe exhibited a distinct ability to recognize AMX and demonstrated a strong linear correlation between the fluorescence intensity (F₅₁₉) and various concentrations of AMX (ranging from 0 to 50 μM) when subjected to the dynamic quenching effect. The probe's detection limit for AMX was 1.048 μM, and when tested in river water, it achieved spiked recoveries ranging from 97.91% to 103.64%. The findings demonstrated a notable decrease in the fluorescence intensity at 519 nm (F₅₁₉) for Cs₄PbBr₆ NCs as the AMX concentration increased. Conversely, the fluorescence intensity at 430 nm (F₄₃₀) for the PCDs remained relatively constant. The Cs₄PbBr₆ NCs@PCDs, as a ratiometric probe, provide higher immunity to interference and greater accuracy, and allow for the quantitative detection of AMX in water sources such as rivers, offering a more novel, efficient and convenient method for AMX detection.