One-pot Synthesis of MnO2CD for Multiple Applications: Detection of Arsenic in Water, Rice Plant and Reversible Temperature Sensing

Abstract

Manganese dioxide-carbon dot (MnO2CD) composite nanoparticles of size 45 nm have been synthesized in a single step from hydrothermal decomposition of KMnO4, polydopamine, and citric acid. The particles show mild emission at 425 nm at excitation wavelength 340 nm with high aqueous dispersion stability and excellent salt stability. The feeble emission property MnO2CD arises because of fluorescence resonance energy transfer from CD to MnO2. In presence of arsenite, the emission intensity of MnO2CD was substantially increased because of redox reaction between MnO2 and arsenite to give soluble Mn2+. This single probe sensor shows selective and sensitive response to arsenite in the linear range of 0 to 100 nM with a detection limit of 5.75nM. Furthermore, the probe shows satisfactory performance for turn-on detection of organoarsenic and organoarsenic compounds such as Dimethylarsenate (DMA), dimethyldithioarsinate (DMDTA), and dimethylmonothioarsinate (DMMTA). Interestingly, this sensor works well for monitoring As in a plant root vascular system through fluorescence and confocal imaging.