Volume 35, Issue 2

Cloud point extraction is a green alternative for separation and preconcentration, whose advantages are magnified by coupling with flow analysis. This results in fast extractions, with improved precision and lower reagent consumption and waste generation. Mechanization has been carried out mainly by flow injection analysis, but feasibility of innovative approaches including sequential injection analysis, multipumping flow systems and lab-in-syringe approaches have also been demonstrated. The approaches for flow-based cloud point extraction are critically revised by taking system designs and operational aspects into account. Applications in environmental, agronomic and food samples as well as biological fluids are also discussed.

Electrochemical magnetoimmunosensors combine a number of issues that guarantee extremely high performance and also compatibility with the study of complex sample matrices. First, analyte immunocapture exploits the high affinity and specificity of antibodies. Second, magnetic particles (MP) provide faster and more efficient immunocapture than binding on two-dimensional structures, separation from nontarget sample components, and concentration of the target analyte. Finally, electrochemical detection supplies sensitivity and fast signal generation using robust and potentially miniaturized measurement equipment and transducers. On the contrary, MP handling is slightly more complex for end-users and more difficult to integrate in point-of-care devices than the manipulation of a classical biosensor. Attempts have been made to automate immunomagnetic binding, and the first robotized systems and platforms for the fluorescent and spectrophotometric detection of magnetoimmunoassays have already reached the market. Among the different types of electrodes available, screen-printed electrodes (SPE) stand out because of their low production cost and yet acceptable performance and interdevice reproducibility, which make them an excellent choice for analytical applications. In addition, each SPE entails a whole electrochemical cell stamped on a planar physical substrate, which makes it possible detection in small volumes and is especially favorable for the magnetic confinement of MP and the integration of microfluidic structures. In this article, we discuss the advantages obtained by using SPE and MP for the production of electrochemical magnetoimmunosensors and the clues for the successful development of such devices. We then revise some of the most outstanding works published in the literature.

Phenolic environmental estrogen (PEE) is one of the most common endocrine disrupting chemicals whose interference with the normal function of the endocrine system in animals and humans raised concern to their potential impact on wildlife and humans health. Research on PEEs calls for a high selectivity analytical methods. Molecularly imprinted polymers (MIPs) are synthetic polymers having a predetermined selectivity for a given analyte, or group of structurally related compounds, which make them ideal materials to be used in analysis of PEEs. During the past few years, a huge amount of papers have been published dealing with the use of MIPs in the analysis of PEEs. In this review, we focus on the recent applications of MIPs to analyze PEEs. We describe the preparation of MIPs and discuss different methods of polymerization. We highlight the latest applications of MIPs in the analysis of PEEs, including nanomaterial MIPs as sorbent for solid-phase extraction and MIPs as electrochemical sensors. This review provides a good platform for the analysis and monitoring of PEEs in complicated matrixes and offers suggestions for future success in the field of MIPs.