<p>Heavy metal ions such as Nickel (Ni), Chromium (Cr), Lead (Pb), Arsenic (As), Cadmium (Cd), etc., have emerged as a critical environmental and public health concern due to its non-biodegradable nature. They cause adverse effects on human health and ecosystems when discharged in excessive amounts through industrial effluents and contaminated water sources. To manage these risks, there is a need for accurate and reliable methods that can effectively detect and monitor heavy metal pollutants. There are conventional methods to identify the presence of heavy metal ions, but necessitate skilled personnel, lengthy procedures, bulky equipment, etc., Recently, electrochemical nanosensors are being employed for detecting these toxic ions as they are cost-effective, highly selective, sensitive, and capable of detecting ions in low concentration ranges. This paper reviews conventional heavy metal detection methods, highlighting their advantages and limitations, and underscores the need for electrochemical nanosensor-based approaches. A systematic overview of nanomaterials, their synthesis strategies, electrochemical sensing principles, as well as detailed discussions on potentiostat design and sensor fabrication methods are provided. Recent trends such as the use of machine learning (ML) models for heavy metal ion prediction and classification is also reviewed. Thus, a consolidated perspective on electrochemical nanosensor technologies and smart potentiostat systems, offering guidance for the development of portable, and smart platforms for real-time heavy metal monitoring is presented.</p> Graphical Abstract <p></p>