Optical aptasensor based on silver nanoparticles for the colorimetric detection of adenosine.

A new and straightforward optical sensor for the colorimetric determination of adenosine (AD) in human urine samples was developed. The sensor comprised silver nanoparticles (AgNPs) as colorimetric elements and anti-AD aptamer (AP) as a recognition probe. In a solution containing AD and high concentration of NaCl, due to the unique binding of AD with AP, the aggregated metal nanomaterials dispersed in the solution, and the color intensity of the solution was changed accordingly.

Hydrazide functionalized magnetic nanoparticles for specific extraction of N-terminal serine and threonine peptides.

In this study, we present hydrazide functionalized magnetic nanoparticles as a sorbent prepared by a new and facile method. Scanning electron microscope and Fourier transform infrared were used for characterizing the synthesized nanoparticles. The ability of the sorbent to extract N-terminal serine and threonine peptides was evaluated.

Plasmid DNA purification by zirconia magnetic nanocomposite.

A zirconia magnetic nanocomposite was prepared by a co-precipitation method in one step. The synthesized nanocomposite was characterized by scanning electron microscopy, energy-dispersive X-ray and Fourier transform infrared spectroscopy. The nanocomposite was applied for the adsorption/desorption of tobacco plant DNA (as a model).

Negative electrospray ionization ion mobility spectrometry combined with microextraction in packed syringe for direct analysis of phenoxyacid herbicides in environmental waters.

A novel method based on microextraction in packed syringe (MEPS) coupled with negative electrospray ionization-ion mobility spectrometry (ESI-IMS) was developed for simultaneous and direct determination of phenoxyacid herbicides in water samples. The effects of various parameters such as pH of the sample solution, sample loading rate, the nature of elution solvent and its volume, and the number of extraction cycles were investigated. The method was exhaustively validated in terms of sensitivity, recovery, reproducibility, and enrichment factor.