Preparation of high quantum yield nitrogen and sulfur co-doped carbon dots for sensitive detection of Cu2+

Abstract

Nitrogen and sulfur co-doped green fluorescent carbon dots (G-CDs) with quantum yield (QY) of 28.26% were synthesized by hydrothermal method with p-phenylenediamine and thiosemicarbazone as precursors. The synthesized G-CDs exhibit good sensitivity and anti-interference ability for detecting copper ion (Cu 2þ ) by fluorescence quenching (λ ex ¼ 390 nm, λ em ¼ 535 nm) with a linear range of 20 to 200 μM and the limit of detection of 4.8 μM. This analytical method has been applied to detect Cu 2þ of the local lake with good accuracy and recovery.