Particle size enlargement and 6-fold fluorescence enhancement of colloidal CdS quantum dots induced by selenious acid.

Herein, colloidal CdS QDs have been synthesized by using cysteine as a stabilizing agent. The interaction between the CdS QDs and selenious acid was monitored by using UV-visible, fluorescence and Fourier transform infrared (FTIR) spectroscopy. The onset of absorption of the CdS QDs (430 nm) was progressively red-shifted upon increase in the concentration of selenious acid at pH 10.

Cysteine-stabilized silver nanoparticles as a colorimetric probe for the selective detection of cysteamine.

The purpose of the present research was to design a method for the colorimetric determination of cysteamine. We have employed cysteine-stabilized silver nanoparticles (AgNPs) as a probe. The addition of cysteamine resulted in the quenching of the 400 nm surface plasmon resonance (SPR) band of the AgNPs.

Spectroscopic investigations on the interaction of thioacetamide with ZnO quantum dots and application for its fluorescence sensing.

The purpose of the present work was to develop a method for the sensing of thioacetamide by using spectroscopic techniques. Thioacetamide is a carcinogen and it is important to detect its presence in food-stuffs. Semiconductor quantum dots are frequently employed as sensing probes since their absorption and fluorescence properties are highly sensitive to the interaction with substrates present in the solution.

Sensitive and selective detection of adenine using fluorescent ZnS nanoparticles.

We have used fluorescent ZnS nanoparticles as a probe for the determination of adenine. A typical 2 × 10(-7) M concentration of adenine quenches 39.3% of the ZnS fluorescence.

Surface-modified CdS nanoparticles as a fluorescent probe for the selective detection of cysteine.

We present a novel method for the selective detection of cysteine, a sulfur-containing amino acid, which plays a crucial role in many important biological functions such as protein folding. Surface-modified colloidal CdS nanoparticles have been used as a fluorescent probe to selectively detect cysteine in the presence of other amino acids in the micromolar concentration range. Cysteine quenches the emission of CdS in the 0.

Photophysics and Photocatalytic Properties of Cd(OH)(2)-Coated Q-CdS Clusters in the Presence of Guanine and Related Compounds.

The photophysics of Cd(OH)(2)-coated Q-CdS in the presence of guanine and related compounds has been examined. Guanine and adenine quench the bandgap emission and reduce the emission lifetime of these particles. Approximately 50% of the bandgap fluorescence is quenched by a low [guanine] (2x10(-5) mol dm(-3)).