Chemiluminescence behaviour of CdTe–potassium permanganate enhanced by sodium hexametaphosphate and sensitized sensing of <scp>l</scp>‐ascorbic acid

A simple and highly sensitive chemiluminescence (CL) method is reported for the determination of naphazoline hydrochloride (NH). It was found that the weak CL from the reaction of luminol and KIO4 in an alkaline medium could be highly amplified by cysteine-capped cadmium telluride quantum dots (QDs) and the enhanced CL was effectively quenched by NH and this finding was utilized as a basis for the determination of NH. The QDs were synthesized in aqueous medium and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis and photoluminescence spectroscopy. A possible mechanism was proposed for the CL system based on radical identification experiments, along with CL spectrum of the system. The experimental parameters were optimized by the reliable response surface methodology (RSM). Under the optimized experimental conditions, the proposed method allowed the determination of NH over the range of 5.0 × 10(-10) -2.0 × 10(-7) mol/L (r(2) = 0.9993, n = 10). The precision (RSD%) of the method, obtained from five replicate determinations of 2.0 and 150 nmol/L NH, was found to be 1.0% and 1.3%, respectively. The method was successfully applied to the determination of NH in pharmaceutical formulations and human urine and serum samples with results corroborated with the aid of those obtained from a standard method.

Section: Introductionmentioning

confidence: 99%

Determination of naphazoline hydrochloride in biological and pharmaceutical samples by a quantum dot‐assisted chemiluminescence system using response‐surface methodology

Imani-Nabiyyi

Sorouraddin

2014

“…Accordingly, the significance of a process that quickly and conveniently detects metal ions in water is presented. Semiconductor nanocrystals (NCs, also known as quantum dots) have excellent photoluminescence (PL) properties such as narrow, tunable symmetric emission spectra, high PL quantum yields (QY) and stability, and therefore have a great potential for applications from chemo/biosensors to solar cells and light emitting diodes (LEDs) (2)(3)(4)(5)(6)(7)(8)(9)(10)(11). Specifically, recent fabrications and applications of NC-based chemical sensors with high selectively and sensitively for sensing transition metal ions have attracted much attention (12)(13)(14)(15)(16)(17).…”

Section: Introductionmentioning

confidence: 99%

Application of hybrid SiO₂‐coated CdTe nanocrystals for sensitive sensing of Cu²⁺ and Ag⁺ ions

Cao

Zhang

et al. 2013

A new ion sensor based on hybrid SiO2 -coated CdTe nanocrystals (NCs) was prepared and applied for sensitive sensing of Cu(2+) and Ag(+) for the selective quenching of photoluminescence (PL) of NCs in the presence of ions. As shown by ion detection experiments conducted in pure water rather than buffer solution, PL responses of NCs were linearly proportional to concentrations of Cu(2+) and Ag(+) ions < 3 and 7 uM, respectively. Much lower detection limits of 42.37 nM for Cu(2+) and 39.40 nM for Ag(+) were also observed. In addition, the NC quenching mechanism was discussed in terms of the characterization of static and transient optical spectra. The transfer and trapping of photoinduced charges in NCs by surface energy levels of CuS and Ag2 S clusters as well as surface defects generated by the exchange of Cu(2+) and Ag(+) ions with Cd(2+) ion in NCs, resulted in PL quenching and other optical spectra changes, including steady-state absorption and transient PL spectra. It is our hope that these results will be helpful in the future preparation of new ion sensors.

Enhanced chemiluminescence of the fluorescein–KIO₄ system by CdTe quantum dots for determination of catechol

Cai

Yang

He³

et al. 2018

In this paper, a novel chemiluminescence (CL) system was introduced based on the use of CdTe quantum dots (QDs) with the mixture solutions of fluorescein and potassium periodate (KIO ) in alkaline medium. The CL signal of an ultra-weak system was strongly enhanced in the presence of QDs. The application of CdTe QDs-fluorescein-KIO system is reported for the first time. It was found that catechol had a diminishing effect on the CL reaction. Under optimal experimental conditions, CL intensity decreased linearly in a 1 to 100 μM catechol concentration range, with a 0.18 μM detection limit. A possible reaction mechanism was proposed according to the results of kinetic analyses, CL spectra, ultraviolet-visible and fluorescence spectra. The results pointed to an efficient energy transfer between the CL energy donor CdTe QDs and acceptor fluorescein. Finally, the CL method was successfully applied to the determination of catechol in environmental water samples.