Bismuth Molybdate/Graphene Nanocomposite for Electrochemical Detection of Mercury

Abstract

We developed a flexible electrode based on a bismuth molybdate/graphene (BiM/GR) nanocomposite for electrochemical detection of mercury (Hg2+). The formation of the BiM/GR nanocomposite was systematically examined with suitable characterization studies. The BiM/GR-modified electrodes exhibit a high electrocatalytic performance toward Hg2+ detection comparable to other electrodes. The excellent electrocatalytic activity of the BiM/GR nanocomposite can be attributed to its good conductivity, synergistic effect, and abundant active site. Notably, the BiM/GR sensor showed good electrochemical sensing performance for Hg2+ in the wide detection range from 0.02 to 149 μM with a good sensitivity of 9.5 μA μM–1 cm2 and an ultralow detection limit of 5.0 nM, which is well below the threshold value set by the World Health Organization (30 nM) and the United States Environmental Protection Agency. More importantly, the BiM/GR nanocomposite-modified electrode was used successfully to detect Hg2+ in river water, corn, and fish samples with satisfactory recovery values.

Boron-Doped Diamond Modified with 4-Mercaptopyridine-Functionalized Gold Nanoparticles for Trace Mercury Detection

“…The low Hg 2+ content poses a significant challenge to the sensitivity and detection limit of the electrochemical sensors. To enhance the performance of sensors, plenty of materials have been proposed as the sensing elements, such as graphene, , oligonucleotides, , metal–organic frameworks, , and other polymers. Fu et al reported a sensor of Zr­(IV)-based MOFs with specifically attached thioether side groups allowing Hg 2+ to be easily adsorbed and detected .…”

4-Mercaptopyridine-Modified Sensor for the Sensitive Electrochemical Detection of Mercury Ions

“…According to the WHO requirement, the limit for Hg 2+ in drinking water is 6 µg/L, which poses a great challenge to the sensors [13]. To improve the performance of the electrochemical sensors, plenty of novel materials have been proposed and applied as the sensing elements, including metal-organic frameworks (MOFs) [14][15][16], graphene [17][18][19], carbon nanotubes [20][21][22], oligonucleotides [23][24][25], etc. For instance, Mariyappan et al reported the electrochemical detection of Hg 2+ using a nanocomposite of a Sr@FeNi-S nanoparticle and carbon nanotube with the limit of detection (LOD) of 0.1 µg/L and a wide linear range of 10 µg/L-55.8 mg/L [26].…”