Standardisation of metalloimmunoassay protocols for assessment of silver nanoparticle antibody conjugates

Silver Nanoparticle-Based Fluorescence-Quenching Lateral Flow Immunoassay for Sensitive Detection of Ochratoxin A in Grape Juice and Wine

A silver nanoparticle (AgNP)-based fluorescence-quenching lateral flow immunoassay with competitive format (cLFIA) was developed for sensitive detection of ochratoxin A (OTA) in grape juice and wine samples in the present study. The Ru(phen)32+-doped silica nanoparticles (RuNPs) were sprayed on the test and control line zones as background fluorescence signals. The AgNPs were designed as the fluorescence quenchers of RuNPs because they can block the exciting light transferring to the RuNP molecules. The proposed method exhibited high sensitivity for OTA detection, with a detection limit of 0.06 µg/L under optimized conditions. The method also exhibited a good linear range for OTA quantitative analysis from 0.08 µg/L to 5.0 µg/L. The reliability of the fluorescence-quenching cLFIA method was evaluated through analysis of the OTA-spiked red grape wine and juice samples. The average recoveries ranged from 88.0% to 110.0% in red grape wine and from 92.0% to 110.0% in grape juice. Meanwhile, less than a 10% coefficient variation indicated an acceptable precision of the cLFIA method. In summary, the new AgNP-based fluorescence-quenching cLFIA is a simple, rapid, sensitive, and accurate method for quantitative detection of OTA in grape juice and wine or other foodstuffs.

Microfluidics-Enabled Diagnostic Systems: Markets, Challenges, and Examples

Microfluidics has become an important tool for the commercial product development in diagnostics. This article will focus on current technical demands during the development process such as material and integration challenges. Furthermore, we present data on the diagnostics market as well as examples of microfluidics-enabled systems currently under commercial development or already on the market.

Contribution of silver nanoparticles to extend Salmonella typhimurium growth under various respiration regimes

Living cells interact with different forms of metal; the resulted biochemical alteration depends on the dose. Over an average dose in ionic form, metals interact with respiration processes at various levels, and it induces oxidative stress by shifting the whole oxydoreduction equilibrium. To correct the toxicity, cell develops different ways to cancel the effect of the exceeded charges, and it reduces the ion to get a more stable form. In the case of nanoparticles, the reactivity of surface has been enhanced that can alter the biological mechanisms; the cell may develop different strategies to minimize this reactivity. The current study is focused on the pursuing of cell behavior regarding the presence of nanoparticles and their associated metals. Nanoparticles have been synthesized using bio-reducing agents and then were structurally characterized using X-ray diffraction, UV-Vis, and infra-red spectroscopy. The oxydoreduction flexibility of the post-synthesis modified nanoparticles was tested in vitro. Interactions with cells were done using Salmonella under various respiration conditions. The final results show the possible correction of oxidative stress effects and the recuperation of respiration.