No abstract

Stable water-soluble CdHgTe nanorods with an emission wavelength at 722 nm, obtained by doping Hg 2+ into CdTe nanorods, has been used as a near-infrared region (NIR) probe to investigate their interaction with copper(II) ions. A new fluorimetric method for the determination of copper(II) ions has been developed based on the quenching effect of copper(II) ions on the emission of CdHgTe nanorods. The mechanism studies show that an effective electron transfer from nanorods to the copper(II) ions occurred based on the coordination reaction between copper(II) ions and the carboxyl groups on the nanorods surface, which could be responsible for the emission quenching of CdHgTe nanorods. Under optimum conditions, the linear range of the calibration curve for the determination of Cu 2＋ is from 8.0×10-9 to 1.0×10 -6 mol/L and the detection limit is 2.0×10 -9 mol/L. Owing to low background interference of NIR measurement, the proposed method displays relative high sensitivity and selectivity. Especially, some physiologically important cations almost do not interfere with the determination of Cu 2＋ . The proposed method was also applied to the determination of trace Cu 2＋ in real aqueous samples with satisfactory results.

A novel peroxyoxalate chemiluminescence system has been designed for the determination of Triton X-100 (TX-100), in which a hydrophobic fluorescent conjugated polymer, poly[2,5-bisnonyloxy-1,4-phenyleneethynylene-9,10-anthrylene] (PPEA) was employed as a fluorophor. A strong enhanced intensity of chemiluminescence (CL) was observed in the presence of TX-100, due to the improved emission efficiency of PPEA in the presence of TX-100. Under optimum conditions, the detection range of Triton X-100 is between 1.0×10 -7 and 1.0× 10 -4 mol•L -1 , with a detection limit at 6.0×10 -8 mol•L -1 . The relative standard deviation is 2.4% (n＝6) for 1.0×10 -6 mol•L -1 Triton X-100. This method provides satisfying results in the detection of TX-100 in nature water and biological samples with high sensitivity and wide linear range.