Indirect Competitive Chemiluminescent Enzyme Immunoassay Method for Determination of Dimethyl Phthalate in Soy Sauce and Liquor

A review on solution- and vapor-responsive sensors for the detection of phthalates

Phthalic acid esters, largely referred to as phthalates, are today acknowledged as important pollutants used in the manufacture of polyvinyl chloride (PVC)-based plastics, whose use extends to almost every aspect of modern life. The risk of exposure to phthalates is particularly relevant as high concentrations are regularly found in drinking water, food-contact materials and medical devices, motivating an immense body of research devoted to methods for their detection in liquid samples. Conversely, phthalate vapors have only recently been acknowledged as potentially important atmospheric pollutants and as early fire indicators; additionally, deposition of these vapors can pose significant problems to the proper functioning of spacecraft and diverse on-board devices, leading to major space agencies recognizing the need of developing vapor-responsive phthalate sensors. In this manuscript we present a literature survey on solution- and vapor-responsive sensors and analytical assays for the detection of phthalates, providing a detailed analysis of a vast array of analytical data to offer a clear idea on the analytical performance (limits of detection and quantification, linear range) and advantages provided by each class of sensor covered in this review (electrochemical, optical and vapor-responsive) in the context of their potential real-life applications; the manuscript also gives detailed fundamental information on the various physicochemical responses exploited by these sensors and assays that could potentially be harnessed by new researchers entering the field.

Development of an immunochromatographic assay as a screen for detection of total phthalate acid esters in cooking oil

Phthalate acid esters (PAEs) contamination raised concerns as a result of migration from food packaging and environmental exposure. Because of the adverse effects of PAE reported in humans, the aim of this study was to examine the ability to screen for the detection these chemicals as an indicator of potential exposure. Too develop a sensitive screening test to determine PAE, a specific polyclonal antibody against phthalic acid (PA), the hydrolysate of PAEs, was used as a marker of total PAEs. This method involved the use of 4-aminophthalic acid (APA) as an immunizing hapten to generate antibody. Subsequently, this antibody conjugated with labeled gold nanoparticles (GNPs) was then used to develop an immunochromatographic assay (ICA) for visually detecting PA. After establishing optimal assay conditions, the ICA strip detected visually PA at 3 μg/ml rapidly in less than 5 min. Further, this assay exhibited reliable specificity for PA with no apparent cross-reactivity with structurally related PAEs. A significant correlation between data obtained with the ICA strip and high-performance liquid chromatography (HPLC) analysis was achieved using cooking oils as model spiked samples. The proposed use of ICA offers an effective tool for rapid on-site screening for total PAEs in cooking oils.

A fluorescent ELISA based on the enzyme-triggered synthesis of poly(thymine)-templated copper nanoparticles

Inspired by the ALP-triggered hydrolysis of the substrate ascorbic acid 2-phosphate as well as the product ascorbate-controlled generation of polyT-CuNPs with bright red fluorescence, we have developed a novel, selective and sensitive fluorescence turn-on assay for ALP activity sensing. Based on the conventional ELISA platform and commercially available antibody-ALP conjugates, an unconventional fluorescent ELISA system has been rationally developed and successfully applied in the quantitative measurement of model antigen proteins using fluorescence spectroscopy and a naked-eye readout under ultraviolet light.