Highly selective detection of phosphate ion based on a single-layered graphene quantum dots-Al3+ strategy

Publication date: 1 February 2018
Source:Talanta, Volume 178
Author(s): Bin Bin Chen, Rong Sheng Li, Meng Li Liu, Hong Yan Zou, Hui Liu, Cheng Zhi Huang
Determination of phosphate ion (PO4^3-) is important in biomedical and environmental arrays because its controlling concentrations are associated with different pathologies or the quality of water. Herein, we report a new type of photoluminescence (PL) probe for highly selective detection of PO4^3- based on a single-layered graphene quantum dots chelating with aluminium ions (s-GQDs-Al³⁺) system. The PL of s-GQDs can be enhanced by Al³⁺ through the aggregation-induced emission enhancement (AIEE) effect. With the addition of PO4^3-, the PL of the s-GQDs-Al³⁺ system is faded away because PO4^3- has stronger coordination with Al³⁺ which results in the elimination of AIEE effect and the decrease in the PL intensity of the s-GQDs-Al³⁺ system. Therefore, the s-GQDs-Al³⁺ system can behave as an on-off type PL probe for PO4^3- detection. It is found that the PL intensity ratio (I/I0) of s-GQDs in the presence of Al³⁺ at 463nm is proportional to the concentration of PO4^3- in the range of 0.25–7.5μM with the limit of detection as low as 0.1μM. This selective assay has a great application prospect in the complex matrixes owing to its simplicity and specificity for PO4^3- detection.

Graphical abstract

http://ift.tt/2y9ZHbg