Materials and design strategies for the electrochemical detection of antineoplastic drugs: Progress and perspectives

Due to the high prevalence of cancer in modern societies, it is crucial to monitor and scrutinize chemotherapeutic medications closely and precisely. Administering antineoplastic drugs to suppress the growth or destroy cancer cells is one of the most effective treatments, which is widely practiced at present. These anticancer drugs are designed to target cancer cells, whereas in a few cases, they could also become toxic to non-cancerous cells, posing risks not only to patients but also to healthcare workers and the soil and aquatic environments. Therefore, the concentrations of these drugs need to be quantified precisely at their nano/picomolar levels to attain better efficacy of the intended treatment, safeguard the patients from adverse effects, and protect the environment. Among various methodologies, electrochemical techniques are highly appreciated owing to their high sensitivity and selectivity, low cost, ease of operation, rapid response, low sample requirement, and ease of miniaturization. Even though hundreds of sensors have been reported for the electrochemical detection of these antineoplastic drugs, only a few reviews highlighted their prominence. While certain aspects of the electrochemistry of antineoplastic drugs can be found in those reviews, many important aspects are still inadequately addressed and remain significantly behind the current state of the art. Thus, we intend to bridge this gap by systematically reviewing the electrochemical sensors developed for the selective detection of various antineoplastic drugs. Significant emphasis has been given to the electrode materials, fabrication procedures, and sensing strategies, as well as a comparison of their analytical performances and evaluation of their advantages and limitations. This review would pave a new path for developing wearable, continuous monitoring point-of-care systems for the on-site and online sensing of multiple chemotherapeutic drugs, ensuring the livability of cancer patients by attaining maximum drug efficacy and minimizing or eradicating their adverse effects on humanity and the environment.