Heavy metals, the common troublemakers among pollutants, have been under the research spotlight. Whether creeping into our surroundings through geological processes or making a grand entrance via human activities like mining, industrial production, and petrochemical plants, these metals have prompted scientific curiosity.
What are heavy metals?
Heavy elements are those with atomic numbers higher than 92. Neptunium (Np) is the first heavy element at atomic number 93. Some heavy elements are made in reactors, while others are crafted in cyclotron experiments.
Why are heavy metals a concern?
Heavy metal toxicity emerges as a significant health threat, with its lurking dangers and associated risks taking centre stage. These metals, devoid of any biological role, persist in forms that are trouble for the human body’s proper functioning. Acting as deceptive elements, they disrupt crucial metabolic processes.
That’s why having accurate and compact technology to detect heavy metals (HMs) is crucial. It helps measure their levels in the environment and identify health concerns caused by their presence.
Electrochemical sensing techniques have recently gained popularity for on-the-spot screening of HM pollutants.
Why?
These methods offer high sensitivity, long-term stability, affordability, compact tools, easy sample handling, and top-notch accuracy. As a result, there is a surge in miniaturised electrochemical devices decked out with diverse nanomaterials.
What is the research?
A team of scholars from Pusan National University (PNU) in South Korea has delved deep into the realm of electrochemical sensors tailored for detecting heavy metals.
“Conventional analytical techniques for Heavy Metals’ detection are difficult for on-field analysis. There is, thus, an urgent need for portable electrochemical sensors that are easy to use, cost-effective, and suitable for rapid on-site detection,” elucidates Professor Seung-Cheol Chang, who led the research.
During their research, the research team at Pusan National University in South Korea systematically examined diverse sensor variants. Noteworthy are screen-printed electrodes (SPEs), paper-based electrodes, and nanomaterial-coated sensors, each engineered from distinct materials such as carbon nanocomposites, metal nanoparticles, and metal-compound nanocomposites.
Based on their meticulous analysis, the research team identified that miniaturised electrochemical sensors utilising screen-printed electrodes (SPEs) and paper-based electrodes present cost-effectiveness and time efficiency advantages. These sensors streamline the analysis process and reduce the required sample and supporting electrolytes, effectively mitigating the constraints associated with traditional laboratory-centric methods.
Moreover, sensors employing nanomaterials showcase elevated specificity and sensitivity. This enables the detection of minuscule amounts of heavy metals with remarkable precision across diverse environmental conditions.
Are there any limitations?
Despite these advancements, the researchers acknowledge existing limitations in electrochemical sensor technology.
Challenges include suboptimal selectivity, insufficient granularity in data capture, and susceptibility to interference from external elements, potentially impacting the accuracy of on-site analyses.
Addressing these challenges remains crucial for further refinement and advancement in the field.
Adding to the complexity, the researchers noted a potential decline in the sensors’ detection efficacy over time attributed to dissolved oxygen species. They stressed the urgency for portable lab-on-a-chip solutions and the widespread production of disposable, flexible, and wearable electrochemical sensors to counteract this issue.
Emphasising the significance of innovation, the researchers highlighted the necessity for groundbreaking electrochemical detection strategies, especially in heavy metal sensing within human biofluid samples such as saliva, blood, and urine.
The Silver Lining
Despite the challenges, the research team expresses confidence in the potential solutions of continuous exploration in electronics, nanotechnology, and materials technology.
They believe that ongoing research efforts can effectively address current limitations, leading to a more accurate on-site detection of heavy metals (HMs). These advancements, in turn, promise to foster a safer and healthier environment.
This study is an illuminating guide to the contemporary progress in electrochemical detection technologies. Positioned as a valuable resource for the present, it also stands as an inspiration for future research endeavours, propelling the field toward ever-greater innovation and impact.
