In this study, we propose a unique use of silver-carbon dot nanohybrid (Ag@CDs) with an average size of 16 nm as a multi-mode sensor for the selective detection of Fe3+ and the construction of logic gates based on these unique detection properties. The Ag NPs exhibit colourimetric sensing and fluorescence quenching in response to Fe3+ in the concentration range of 10-100 ppm, with the carbon dots acting as the fluorescent entity. Surprisingly, the nanohybrid was shown to have excellent sensitivity to Fe3+, resulting in aggregation and formation of yellowish-brown clumps. When the reaction mixture was treated with Fe3+, there was a discernible change in the colour of the assay mixture and fluorescence quenching. That is, the Ag@CDs acted as a calorimetric and fluorescence multi-mode sensor. Even in interfering groups in the natural river water sample, the produced nanohybrid displayed good selectivity towards Fe3+, with a minimum LOD of 0.76 ppm. Further, we constructed an advanced logic system, IMP-OR gate, by using additional inputs - ascorbic acid and urea.
Keywords: Ag NPs; Ag@CDs; Carbon dots (CDs); Heavy metal sensors; Logic operations.
Copyright © 2022 Elsevier Ltd. All rights reserved.