Ratiometric sensing of MnO4− using one-pot hydrothermally synthesized intrinsic dual-emission carbon dots

Abstract

Permanganate (MnO₄⁻) is a highly potent oxidant, where excessive intake can lead to serious health consequences. Hence, the qualitative and quantitative detection of permanganate holds significant importance. In this study, blue/yellow intrinsic dual-emission carbon dots (BYIDE-CDs) were prepared by a one-pot hydrothermal method with N-doped sources. The resulting BYIDE-CDs exhibited stable fluorescence intensity across a wide pH range and showed resilience to high ionic strength and continuous UV irradiation. They demonstrated high performance for detecting MnO₄⁻ with a wide linear range (0.1–75 μM), low detection limit (0.014 μM), and high selectivity. The mechanism of MnO₄⁻ detection involved both dynamic quenching and an internal filtration effect (IFE), with dynamic quenching playing a predominant role. Furthermore, BYIDE-CDs were applied for detecting MnO₄⁻ in river water samples, showing high recovery rates (91.9–103.5%) and low relative standard deviation (≤3.7%). Overall, BYIDE-CDs offer a promising platform for sensitively and selectively detecting MnO₄⁻ in various applications.