Current Perspective and Developments in Electrochemical Sensors Modified with Nanomaterials for Environmental and Pharmaceutical Analysis

Background: Over the past few decades, environmental pollution has appeared to be one of the most crucial global problems. The widespread intensification of numerous hazardous pollutants in the environment need the modern researchers to develop viable, reproducible and cost-effective determination tools for the reliable environmental analysis. The beneficial, as well as perilous, biological compounds are receiving growing interest due to their variable composition which produces advantageous and toxic impacts on human and the environment. Several conventional analytical methods have been established for the pharmaceutical and environmental analysis. However, certain drawbacks limited their practices in the modern rapidly growing era of science and technology. The development of electrochemical sensors has emerged as more beneficial and promising tool as against other traditional analytical approaches, in terms of simplicity, cost-effectiveness, sensitivity, stability and reliability. Nonetheless, the over potential and low anodic/cathodic current response are both considered as bottlenecks for the determination of electroactive entities exploiting electrochemical sensors. Interestingly, these problems can be easily resolved by modifying the electrodes with a variety of conductive materials, especially nanostructures. Objective: This review covers different electrochemical methods, reported in the literature, for the environmental and pharmaceutical analysis through simple and cost-effective nanostructures-based sensors. The electrochemical techniques with different modes and the modification of electrodes with highly conductive and prolific polymeric and nanostructured materials used for the determination of different environmental and pharmaceutical samples are the main prominence of this review. Various kinds of nanomaterials, e.g. metal, metal oxide and their composites, have been synthesized for the fabrication of sensitive electrodes. Conclusion: Nanostructures played a pivotal role in the modification of electrodes, which substantially enhanced the capability and sensitivity of electrochemical sensors. The proper modification of electrodes has materialized the swift detection of electroactive compounds at very low limits and offered the feasible determination procedure without any kind of signal fluctuation and over potential. In crux, due to their enhanced surface area and excellent catalytic properties, nanomaterials recently appeared as the most promising candidates in the field of electrode modification and significantly impacted the detection protocols for various environmental pollutants, viz. pesticides, metal ions and drugs.