Chiral CdSe nanoplatelets as an ultrasensitive probe for lead ion sensing

Xiongbin Wang (1) , Junjie Hao (1, 2) , Jiaji Cheng (3, 4) , Junzi Li (3) , Jun Miao (5, 6) , Ruxue Li (1) , Yiwen Li (1, 5) , Jiagen Li (7) , Yuhui Liu (1) , Xi Zhu (7) , Yanjun Liu (1) , Xiao Wei Sun (1) , Zikang Tang (5) , Marie-Hélène Delville (2) , Tingchao He (3) , Rui Chen (1)

1 Department of Electrical and Electronic Engineering
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 College of Physics and Energy
4 School of Materials Science and Engineering
5 The Institute of Applied Physics and Materials Engineering
6 Department of Materials Science and Engineering
7 School of Science and Engineering

As opposed to traditional photoluminescence and ultra-violet based optical sensing, we present here a sensing system based on resolved optically active polarization with promising applications. It is based on the ultrathin CdSe nanoplatelets (NPLs) when modified with either L or D-cysteine molecules (L/D-cys) as bio-to-nano ligands. The chiral ligand transfers its chiroptical activity to the achiral nanoplatelets with an anisotropy factor of ∼10−4, which unlocks the chiral excitonic transitions and allows lead ion detection with a limit of detection (LOD) as low as 4.9 nM. Simulations and modelling based on time-dependent density functional theory (TD-DFT) reveal the chiral mechanism of L/D-cys capped CdSe NPLs. The presented CD-based sensing system illustrates an alternative possibility of using chiral CdSe NPLs as competitive chiral sensors for heavy metal ion detection.

Domaines: Chimie analytique; Matériaux

Xiongbin Wang, Junjie Hao, Jiaji Cheng, Junzi Li, Jun Miao, et al.. Chiral CdSe nanoplatelets as an ultrasensitive probe for lead ion sensing. Nanoscale, 2019, 11 (19), pp.9327-9334. ⟨10.1039/c8nr10506e⟩. ⟨hal-02138867⟩