Recent Advances in Electrochemical Monitoring of Chromium

Abstract

The extensive use of chromium by several industries conducts to the discharge of an immense quantity of its various forms in the environment which affects drastically the ecological and biological lives especially in the case of hexavalent chromium. Electrochemical sensors and biosensors are useful devices for chromium determination. In the last five years, several sensors based on the modification of electrode surface by different nanomaterials (fluorine tin oxide, titanium dioxide, carbon nanomaterials, metallic nanoparticles and nanocomposite) and biosensors with different biorecognition elements (microbial fuel cell, bacteria, enzyme, DNA) were employed for chromium monitoring. Herein, recent advances related to the use of electrochemical approaches for measurement of trivalent and hexavalent chromium from 2015 to 2020 are reported. A discussion of both chromium species detections and speciation studies is provided.

In situ electro-organic synthesis of hydroquinone using anisole on MWCNT/Nafion modified electrode surface and its heterogeneous electrocatalytic reduction of toxic Cr(vi) species

“…13B) which is comparable with other reports. [72][73][74] The selectivity of the chemically modied electrode was tested with various referencing systems like copper, ferrous, nitrite, zinc, sulfate, calcium, nitrate and cadmium as in Fig. 13C, but there were no specic current signals noticed highlighting the specicity of the GCE/Nf-MWCNT@HQ for the Cr(VI) sensing.…”

“…[45][46][47] In this connection, Pt and Au nanoparticle-based chemically modied electrodes have oen been worked as a sensor for this purpose. 48,49 Indeed, due to the high cost of the precious metals and surface-fouling of the chemically modied electrodes restrict the electrochemical procedures for further electroanalytical applications. Alternately, mediators modied electrodes like MWCNT/quercetin-SPCE, 46 Chit/MWCNT@MnO x -nanoparticle, 50 AuNP/polyaniline-co-polytoluidine (PoT), 51 g-C 3 N 4 /Ag/Nf/GCE, 52 polyoxometalate 53 and ZnO-Fe 2 O 3 (ref.…”

Carbon Nanomaterials (CNMs) and Enzymes: From Nanozymes to CNM-Enzyme Conjugates and Biodegradation

“…Enzymes supported on nanomaterials can be very convenient to detect pollutants for environmental monitoring through the development of sensitive sensors, but also for their removal from polluted waters [ 382 ]. For example, CNMs coupled to enzymes can be applied for the electrochemical monitoring of chromium [ 383 ]. CNDs’ fluorescence has also been envisaged for the optical detection of organic pesticides through coupling with an enzymatic reaction [ 384 ].…”

Hybrid Materials Based on Conducting Polymers for Nitrite Sensing: A Mini Review

“…These properties make them very promising in the field of electrochemistry. Therefore, nanomaterials, especially carbon nanomaterials (CNMs) and metallic nanoparticles (MNPs) are widely used to develop electrochemical sensors [32–39]. They also have shown excellent results for the detection of nitrite [25, 40–42].…”