Chemiluminescence Of Quantum Dot Organo-Modified Hydrotalcite Nanocomposites And Its Application

Considerable interest has been focused on2-dimensional host-guest nanocomposite materials fabricated by co-intercalation of organic dye and surfactant into the galleries of layered double hydroxides (LDHs). It was concluded that the intercalated chromophores exhibited enhanced thermal stability and highly oriented photoluminescent functionality from individual components alone. These interesting reports inspire us to investigate chemiluminescence (CL) properties of these novel host-guest nanocomposite materials. The main research is as follows:(1) We fabricate an oriented luminescent quantum dot (QD)-LDH nanocomposite material by the highly orderly and alternate assembly of trace CdTe QDs in dodecylbenzene sulfonate bilayer bunches on the organo-modified LDH exterior surfaces. Interestingly, the novel QD-LDH nanocomposites can remarkably amplify CL of luminol-H2O2system, which is attributed to an inhibition of QDs oxidation by H2O2, an increase in the radiative decay rate and an inhibition in the non-radiative relaxation of QDs. In addition, a novel flow-through column-based CL resonance energy transfer is fabricated using luminol as energy donors and the solid luminescent QD-LDH nanocomposites as energy acceptors for signal amplification. The applicability of this flow-through column is evaluated by determining H2O2using luminol-H2O2CL system. Finally, the proposed method has been successfully applied to detect H2O2in snow samples, and the results are agreed with those obtained by the standard spectrophotometric method.(2) It is found that the novel QD-LDH nanocomposites are able to extraordinarily improve an ultra-weak CL emission from peroxynitrous acid (ONOOH). The enhanced CL emission is attributed to the electrostatic concentration of peroxynitrite (ONOO") onto the orderly surface of the QD-organo-modified LDHs as well as the hydrophobic microenvironment of the organo-LDHs, facilitating the production of superoxide radical (’O2) and hydroxyl radical (OH). In addition, the CL intensity increases with increasing the concentration of nitrite in a wide range of1.0-1000μM with a detection limit of0.3μM (S/N=3). Therefore, the proposed method is applied for the selective and sensitive detection of nitrite in sausage samples. The results of the proposed method for sensing nitrite in real samples are agreed with those obtained by the standard spectrophotometric method.