Roles of CdS quantum dots in 1,1'-oxalyldiimidazole chemiluminescence.

The roles of CdS nanocrystals (quantum dots) stabilized by oleic acid ligands in toluene were investigated in the 1,1'-oxalyldiimidazole chemiluminescence (ODI-CL) reaction generated under various environmental conditions. CdS excited by high-energy intermediates formed in ODI-CL reaction emitted dim CL. Also, CdS acted as a catalyst to enhance the yield of high-energy intermediates, capable of transferring energy to fluorescent molecules, in aqueous ODI-CL reactions, whereas it acted as a strong quencher, capable of inhibiting the CL emission of excited fluorescent molecules, in non-aqueous ODI-CL reactions. Based on the role of CdS in the aqueous ODI-CL reaction, the limit of detection (LOD = signal/noise = 3, 0.1 μM) determined to quantify glucose using aqueous ODI-CL reaction in the presence of 2.75 μM CdS was four times lower than that in the absence of CdS. The range of recovery determined in the aqueous ODI-CL reaction in the presence of CdS was 91.7-104%. We expect that the aqueous ODI-CL reaction in the presence of CdS can be applied as a highly sensitive sensor in various research fields such as bioanalytical chemistry, environmental engineering, homeland security, and toxicology.