Paper carbon dot based fluorescence sensor for distinction of organic and inorganic sulphur in analytes

Abstract

In this work a paper carbon dot (PCDs) based fluorescence sensor was developed which can distinguish between the organic and inorganic sulphur in analytes. PCDs were prepared from paper ash. Further, a conjugate paper carbon dot–Au³⁺ (PCD–Au³⁺) system was used to detect organic and inorganic sulphur-bearing analytes based on PL properties. It was found that the PCD–Au³⁺ system showed enhanced PL behavior towards organic and decreased PL behavior towards inorganic sulphur-bearing analytes. Thus this system could successfully detect and distinguish between organic and inorganic sulphur-bearing compounds. The system was successfully applied in the analysis of real samples like “milk”. A probable mechanistic explanation for the different optical behaviour towards organic and inorganic sulphur is also discussed in this paper.