Bio- and Biomimetic Receptors for Electrochemical Sensing of Heavy Metal Ions

Abstract

Heavy metals ions (HMI), if not properly handled, used and disposed, are a hazard for the ecosystem and pose serious risks for human health. They are counted among the most common environmental pollutants, mainly originating from anthropogenic sources, such as agricultural, industrial and/or domestic effluents, atmospheric emissions, etc. To face this issue, it is necessary not only to determine the origin, distribution and the concentration of HMI but also to rapidly (possibly in real-time) monitor their concentration levels in situ. Therefore, portable, low-cost and high performing analytical tools are urgently needed. Even though in the last decades many analytical tools and methodologies have been designed to this aim, there are still several open challenges. Compared with the traditional analytical techniques, such as atomic absorption/emission spectroscopy, inductively coupled plasma mass spectrometry and/or high-performance liquid chromatography coupled with electrochemical or UV–VIS detectors, bio- and biomimetic electrochemical sensors provide high sensitivity, selectivity and rapid responses within portable and user-friendly devices. In this review, the advances in HMI sensing in the last five years (2016–2020) are addressed. Key examples of bio and biomimetic electrochemical, impedimetric and electrochemiluminescence-based sensors for Hg2+, Cu2+, Pb2+, Cd2+, Cr6+, Zn2+ and Tl+ are described and discussed.

An Impedimetric Biosensing Strategy Based on BicyclicPeptides as Bioreceptors for Monitoring h-uPA Cancer Biomarkers

“…Moreover, peptides have become an effective and important alternative to antibodies as bioreceptors in the development of novel diagnostic tools, while providing several advantages owing to their stability, ease of synthesis, and the engineering of their structure [3]. Among others, these properties help in decreasing the steric hindrance of the receptors, thus allowing the increase in active sites to capture the analytes of interest, leading to an enhanced sensitivity of the biosensing platforms toward several bio-and non-bio molecules, such as heavy metals (lead, mercury, and cadmium), DNA, peptides, cells, and proteins [4][5][6]. The application of peptides as bioreceptors to detect target proteins and antibodies is well known, as witnessed by the high number of methodologies and tools used in clinical diagnostics and medical surveys [7].…”

Identification of Cadmium Compounds in a Solution Using Graphene-Based Sensor Array

“…In graphene-based sensors, the choice of the modified molecule on graphene is key to providing the ability to capture the target molecule. When the target is a heavy metal, chelating agents or aptamers that specifically capture heavy metals are typically used [ 28 , 29 , 30 , 31 ]. Chelating agents are molecules that can capture metal atoms using multiple coordination sites, and various molecules have been reported as chelating agents [ 32 , 33 , 34 ].…”

Influence of the synthesis parameters on the efficiency of fluorescent ion-imprinted polymers for lead detection

“…The removal of the template creates cavities inside the polymer network that can selectively rebind this target during the sensor use while associated with a mass, electrical or optical transducing mode. When metal ions are targeted, sensors prepared with ion-imprinted polymers (IIPs) are mainly based on electrochemical measurements because of the electro-activity of these ions [19][20][21][22]. However, optical-based sensors, and particularly fluorescent ones, are highly sensitive and adapted to miniaturization.…”