One-step facile synthesis of novel β-amino alcohol functionalized carbon dots for the fabrication of a selective copper ion sensing interface based on the biuret reaction

Abstract

In this paper, a facile and one-step hydrothermal carbonization approach has been developed for the first time to synthesize β-amino alcohol functionalized fluorescent carbon dots (CDs) with L-phenylalaninol as the sole precursor source. The present CDs with β-amino alcohol moieties attached to the surface were successfully applied to fabricate a novel, simple fluorescent sensing interface for selective detection of copper ions under basic conditions based on the biuret reaction. The added copper ions, not only lead to the specific cross-linked formation of the violet complex with the two β-amino alcohol units on the surface of the CDs, but also in turn lead to the aggregation of the functionalized CDs and induce fluorescence quenching. Such fluorescence responses can be used for monitoring copper ions in the range of 0.01–100 μmol L⁻¹ under basic conditions with the limit of detection (LOD) as low as 3.2 nmol L⁻¹. Moreover, the proposed fluorescent sensor can resist interferences from other metal ions and can be employed for the detection of copper ions in water samples. Due to the simplicity and effectiveness, it exhibits great promise as a practical sensing platform for copper ions especially under basic conditions.