Selective Optode Membranes for Heavy Metal Ion Detection.

Synergy Effects in Heavy Metal Ion Chelation with Aryl- and Aroyl-Substituted Thiourea Derivatives

“…Among the most toxic environmental pollutants are heavy metals. − In addition to their toxicity, their persistence in the environment, since they are non-biodegradable; their tendency to biomagnificate; and their bioaccumulative nature make them contaminants whose detection and removal are essential. − Several kinds of heavy metal-detection sensors have been developed, such as biosensors, − electrochemical sensors, − nanomaterial-based sensors, − and optical sensors. − Today, intense research activity is focused on increasing both the sensitivity and selectivity in detection by these devices. − In this way, thiourea derivatives have been developed as a new type of organic ionophores for heavy metal ion selective electrodes. , One of the processes to eradicate such pollutants is chemical remediation, which consists of the complexation of the ions using chelating ligands. − Thiourea derivatives are promising chelating agents of metal cations that have also been proposed for heavy metal ion removal. − Both for sensing and for removal reasons, understanding heavy metal–ionophore activity by organic compounds is thus of high relevance. − In this context, several studies have focused on metal complexes with thiourea derivatives. Coordination chemistry of alkyl and acyl­(aroyl) thioureas of Pt­(II), Pd­(II), and Rh­(III) was reviewed by Koch; the chemistry and metal complexes of acyl-thiourea compounds were recently reviewed in ref ; and uranyl complexes have also been reported with thiourea derivatives …”