Miniaturized electrochemical biosensor based on whole‐cell for heavy metal ions detection in water

Abstract

The heavy metals pollution represents one of the important issues in the environmental field since it is involved in many pathologies from cancer, neurodegenerative, and metabolic diseases. We propose an innovative portable biosensor for the determination of traces of trivalent arsenic (As(III)) and bivalent mercury (Hg(II)) in water. The system implements a strategy combining two advanced sensing modules consisting in (a) a whole cell based on engineered Escherichia coli as selective sensing element towards the metals and (b) an electrochemical miniaturised silicon device with three microelectrodes and a portable reading system. The sensing mechanism relies on the selective recognition from the bacterium of given metals producing the 4‐aminophenol redox active mediator detected through a cyclic voltammetry analysis. The miniaturized biosensor is able to operate a portable, robust, and high‐sensitivity detection of As(III) with a sensitivity of 0.122 µA ppb−1, LoD of 1.5 ppb, and a LoQ of 5 ppb. The LoD value is one order of magnitude below of the value indicated to WHO to be dangerous (10 μg/L). The system was proved to be fully versatile being effective in the detection of Hg(II) as well. A first study on Hg(II) showed sensitivity value of 2.11 µA/ppb a LOD value of 0.1 ppb and LoQ value of 0.34 ppb. Also in this case, the detected LOD was 10 times lower than that indicated by WHO (1 ppb). These results pave the way for advanced sensing strategies suitable for the environmental monitoring and the public safety.

Development of Colorimetric Whole-Cell Biosensor for Detection of Heavy Metals in Environment for Public Health

“…Thus, these three fluorescent metal-sensing strains could be used to detect hazardous heavy metals at concentration ranges that could have practical uses. Most existing WBC developments need a complicated instrument for detecting fluorescence [ 21 ]. From the production process perspective, our colorimetric biosensor system is easier to use because of its simple and visible detection platform.…”

Immobilized Enzyme-based Novel Biosensing System for Recognition of Toxic Elements in the Aqueous Environment

“…Cell-based biosensing systems were already applied to monitoring heavy metal pollution in water sources including "Cu 2+ '' pollution (using microbial fuel based-biosensor "Escherichia coli Rosetta genetically modified strain") with a LoD of 28 µM [92], contamination with As 3+ and Hg 2+ could be detected with a LOD of 20 µM and 0.498 µM, respectively using an electrochemical cell-based biosensor [93]. Moreover, using an E. coli-arsR/zntA strain with an insertion in arsAp::egfp cell-based biosensor was used to determinate the presence of Pb 2+ contamination with a LoD of 2.06 µM in water artificially contaminated samples [94], and for Cd 2+ contamination in environmental water samples, using a TOP10/pPcad-ind biosensor (E. coli genetically modified strain tolerant to cadmium) with a LOD of 0.049 μM and 0.024 μM of Cd 2+ of exposure in early exponential and lag phase respectively [95].…”

Novel Trends in Electrochemical Biosensors for Early Diagnosis of Alzheimer’s Disease

“…Many biomarkers including metal ions or posttranslational protein modifications are still neglected. Heavy metals have been analyzed by electrochemical biosensor from water in the work of Sciuto and coauthors (2020), copper from water samples was determined in the work of Cui and coauthors (2014), and iron from the water was tested in the work of Kamal and coauthors (2014) [83][84][85]. Glycan electrochemical biosensor for cancer diagnosis was presented in the work of Kveton and coauthors (2019), the electrochemical behavior of phosphotyrosine was observed in the work of Popa and Duculescu (2013), and dual-mode sensor using an electrolyte-insulator-semiconductor fieldeffect device coupled with nanoplasmonic effects was developed for protein phosphorylation detection in the work of Bhalla and coauthors (2015) [86][87][88].…”