-
[show abstract]
[hide abstract]
ABSTRACT: A new synchronous fluorescence method was developed for the rapid determination of Cu2+ with functional CdS nanoparticles as a probe, based on the fluorescence quenching of functional CdS. The synchronous fluorescence
peak is located at 304nm, scanning with excitation and emission wavelengths of 255 and 460nm (Δλ = λ
em ‑ λ
ex = 205nm), respectively. Under optimum conditions, a linear relationship was found between the relative synchronous fluorescence
intensity and the concentration of Cu2+ in the range 0.09 to 27.0μg L−1. The limit of detection was 3.2ng L−1. Compared with other general fluorescent methods for the determination of Cu2+, the proposed method had a wider linear range and improved sensitivity. The quenching mechanism has also been discussed.
Moreover, analytical application of the method was successfully demonstrated by analysis water samples.
Microchimica Acta 02/2009; 164(3):453-458. · 3.03 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Based on the strong enhancement effect of silver ion on resonance light-scattering intensity of functional CdS nanoparticles, a new direct quantitative determination method for silver ion was established. Under the optimum conditions, the response signal is linearly proportional to the concentration of silver ion. The linear range is 5.0x10(-9)-2.0x10(-6) mol L(-1). The proposed method was applied to determine silver ion in river water samples.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 08/2008; 71(5):1701-3. · 2.10 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Based on the characteristics of synchronous fluorescence spectroscopy (SFS), a new method with high sensitivity and selectivity was developed for rapid determination of silver ion with functional cadmium sulphide (CdS) nanoparticles as a fluorescence probe. When Delta lambda (lambda(em) - lambda(ex)) = 215 nm, maximum synchronous fluorescence is produced at 304 nm. Under optimal conditions, functional cadmium sulphide displayed a calibration response for silver ion over a wide concentration range from 0.8x10(-10) to 1.5x10(-8) mol L(-1). The limit of detection was 0.4x10(-10) mol L(-1) and the relative standard deviation of seven replicate measurements for the lowest concentration (0.8x10(-10) mol L(-1)) was 2.8%. Compared with several fluorescence methods, the proposed method had a wider linear range and improved the sensitivity. Furthermore, the concentration dependence of the synchronous fluorescence intensity is effectively described by a Langmuir-type binding isotherm.
Analytica chimica acta 07/2008; 616(2):170-6. · 4.31 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The interaction of poly(diallyldimethyl ammonium chloride) (PDDA) with dodecyl benzene sulfonic acid sodium (DBS) has been studied by fluorescence spectra. The fluorescence of DBS can be greatly enhanced by addition of PDDA, owing to the interaction between PDDA and DBS. The enhancement intensity of fluorescence was proportional to the concentration of DBS over the range 2.5x10(-7) to 9.6x10(-5)molL(-1). Its detection limit is 3.5x10(-7)molL(-1). The method has high sensitivity and selectivity and was applied to the determination of trace amounts of DBS in water samples with satisfactory result.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 01/2007; 65(5):1131-3. · 2.10 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A new fluorescence method for the detection of proteins with novel composite nanoparticles (CdS/PPA) has been developed. The composite nanoparticles have been prepared through an in-situ polymerization method under ultrasonic irradiation. The surface of the composite nanoparticles was covered with functional groups (-COOH). These groups may play a major role in the improving the water solubility and biocompatibility of the nanoparticles. The composite particles is combined with proteins in NaAc-HCl buffer solution (pH=1.99), which can result in strong fluorescence, and the response is linearly proportional to the concentration of proteins. In lambdaem/lambdaex=650 nm/365 nm place (the stoke' shift is 285 nm), its fluorescent strength reaches the maximum. Under the optimum conditions, the linear range is 0.10-20.0 microg.ml(-1) with the detection limit of 41 ng.ml(-1) for HSA, and 0.10-15.0 microg.ml(-1) with the detection limit of 35 ng.ml(-1) for Human gamma-IgG . The method has been applied to the determination of the total protein in human serum samples collected from the hospital and the results are satisfactory.
Analytical and Bioanalytical Chemistry 09/2006; 385(8):1457-61. · 3.78 Impact Factor
