Zn(ii) and Cu(ii) complexes are used in the recognition and sensing of adrafinil through an easy-to-detect fluorescence response.

In this experimental study, we developed lateral flow immunoassay strips for the detection of Escherichia coli. For labelling, gold nanoparticles were prepared and modified with a Raman label. As a result of this, not only colorimetric responses but also Raman responses were obtained from the same strips. The color and Raman intensities were employed for the quantitative determination of Escherichia coli. The employment of two different detection methods strengthens the quantitative determination of Escherichia coli by lateral flow immunoassay, which is mostly used for qualitative detection or sometimes the semi-quantitative determination of samples. After careful optimization and validation steps, the developed strips allowed the highly sensitive determination of Escherichia coli in water and urine samples.

This paper describes a lipoic acid capped europium nanoparticle-based assay for the fluorimetric detection of primary amines. The assay is based on fluorescence quenching resulting from complex formation between amines and lipoic acid on the surface of europium nanoparticles. For the application of the assay, the aminoglycosides were determined in pharmaceuticals and milk. The determination of the aminoglycosides were conducted via fluorescence quenching at 315 nm (λ_ex = 280 nm) at a pH of 5. The metal enhanced fluorescence method with gold nanoparticles was used, in order to enhance the fluorescence of europium nanoparticles. In this manner, the detection limits of aminoglycosides were lowered. The Stern–Volmer constants and the ground-state UV spectra of interaction proved the static quenching that stemmed from the reaction between amines and lipoic acid. Three members of aminoglycosides; amikacin, gentamicin and tobramycin were quantified in the range of 0.75–27.5 μg mL⁻¹, 0.40–26 μg mL⁻¹ and 0.20–25 μg mL⁻¹, respectively.