Felodipine Determination by a CdTe Quantum Dot-Based Fluorescent Probe

Abstract

In this work, a CdTe quantum dot-based fluorescent probe was synthesized to determine felodipine (FEL). The synthesis conditions, structure, and interaction conditions with FEL of CdTe quantum dots were analysed by fluorescence spectrophotometry, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV–visible spectroscopy, and TEM. The CdTe QD concentration was 2.0 × 10−4 mol/L. The amount of quantum dots controlled in the experiment was 0.8 mL. The controlled feeding ratio of N (Cd2+):N (Te2−):N (TGA) was 2:1:4, the heating temperature was 140 °C, the heating time was 60 min, and the pH of the QD precursor was adjusted to 11 for subsequent experiments. The UV–visible spectrum showed that the emission wavelength of CdTe quantum dots at 545 nm was the strongest and symmetric. The particle size of the synthesized quantum dots was approximately 5 nm. In the interaction of CdTe quantum dots with FEL, the FEL dosage was 1.0 mL, the optimal pH value of Tris-HCl buffer was 8.2, the amount of buffer was 1.5 mL, and the reaction time was 20 min. The standard curve of FEL was determined under the optimal synthesis conditions of CdTe quantum dots and reaction of CdTe quantum dots with FEL. The linear equation was Y = 3.9448x + 50.068, the correlation coefficient R2 was 0.9986, and the linear range was 5 × 10−6–1.1 × 10−4 mol/L. A CdTe quantum dot-based fluorescent probe was successfully constructed and could be used to determine the FEL tablet content.

Study of the Optical Properties of 3MPA CdTe and 3MPA CdTe/CdSe Quantum Dots at PH 12 in Different Periods of Time

“…It can be attributed to NP's regular growth of nucleation or particle formation phase during their reaction periods [31][32][33]. The increase in the uniformity of the intensities of the fluorescence peaks can be attributed to the decrease of the precursor Cd +2 and Te -2 ions in the solution [34,35], representing surface defects and a fluorescence inactivation factor [36,37]. The values of the full width at half maximum (FWHM) are less than 50 nm during the interaction, indicating that CdTe QDs without surface defects, giving them good optical properties.…”

High-throughput separation of microalgae on a runway-shaped channel with ordered semicircular micro-obstacles

“…Consequently, microfluidic devices designed for active sorting encounter limitations in many practical applications. The main types of passive sorting include packed flow fractionation (PFF) [10], deterministic lateral displacement (DLD) [11], and inertial microfluidics [12]. Passive techniques employ both different geometrical channel and fluidic kinetic properties to perform high-purity separation for many different cells.…”

Editorial for a Special Issue of Selected Papers from the 23rd Annual Conference and 12th International Conference of the Chinese Society of Micro-NanoTechnology (CSMNT 2021)

“…Finally, some authors constructed a CdTe quantum dot-based fluorescent probe that can be used to determine felodipine content; there was no substantial difference between the results of the determination method and the labelled felodipine tablet contents. Therefore, this method can be used to determine the felodipine content of drugs and various substances accurately and reliably using simple reaction conditions that are easy to control [ 17 ].…”