Sensing materials with a concurrent sensitivity: design, synthesis and application in multisensory systems

Abstract

A series of novel sensing materials with concurrent sensitivity, namely the porphyrins [free-base, Mn(III) and Fe(III) complexes], functionalized with crown-ether or aza-crown (cyclam) pendant groups, were synthesized and tested as ionophores for polymeric membrane electrodes. Several aspects were studied in order to evaluate the functionality and the desired sensitivity of resulting crown-porphyrins hyphenated ionophores, among them the nature and the size of crown fragment cavity, the length of the alkyl pendant incorporating the crown-ether unit, the presence and the nature of central metal ion both in porphyrin and crown macrocycles.

A quantitative description of the voltammetric time series of unclosed electric circuits for detection of differences between different potentiostats/galvanostats

“…The vast majority of papers 1 in the field of multisensory systems are devoted to the development of new sensitive elements and their combinations (polymer films, nanoparticles, composite materials, etc. ).…”

Photochromic Paper Indicators for Acidic Food Spoilage Detection

“…A tremendously important and yet unexplored application of SPs incorporated in paper substrates would be in the smart food packaging area. In fact, the photoactivated acid recognition properties of SPs, combined with the mechanical and chemical stability, nontoxicity, and white contrast of paper, could constitute a cost-effective detection technology that could be directly integrated in the packaging material to allow a practical monitoring of the food state to the end user, through wireless detection or naked eye visualization. , In this context, although several types of colorimetric, optical, electrochemical sensors, radio frequency identification tags, electronic noses, and biological and enzymatic assays have been proposed, − their use is often impractical for the shelf-life evaluation and the quality control operations in food processing industries because of their complex design, long detection times, high costs, chemical and physical (i.e., temperature, humidity, electromagnetic fields) interferences, time consuming procedures, and uneasy multivariate statistical methods or mathematical modeling for data interpretation. , Moreover, to assess the freshness and quality of fish, meat, alcoholic beverages, and dairy products, much effort has been devoted to the development of chemoresponsive materials, based on fluorescent dyes, modified carbon nanotubes and conductive polymers, and of sophisticated analytical methods (i.e., electrokinetic chromatography, capillary zone electrophoresis) that can target volatile compounds associated with microbial decomposition, such as biogenic amines, rather than acidic byproducts. ,− …”

Fast Optical Sensing of Metals: A Case Study of Cu2+Assessment in Soils

“…The application of chemical sensors and multisensory systems has found a lot of interest for environmental monitoring tasks, and for transition and heavy metal ions detection, in particular due to the obvious advantages of simple preparation and handling, low cost, reasonable selectivity and improved sensitivity. [16][17][18] The development of novel sensing materials with analytically useful sensitivity toward metal cations for application in optical chemical sensors is nowadays a challenging task. Ionophores are key components that significantly contribute to the selectivity of polymeric membrane sensors.…”