Research into metal-NP-based electrochemical detection for bioanalysis has drawn increasing attention from scientists in recent years owing to their extreme usefulness. Many types of metal NPs with different sizes and compositions are now available, facilitating their use in electrochemical applications as both chemical sensors and biosensors. These metal-NPs are of high surface area, high mechanical strength but ultra-light weight, rich electronic properties, and excellent chemical and thermal stability [13]. The unique properties of nanoscale materials led to very high sensitivity that is a gold purpose in biological assays. Currently, highly sensitive methodologies are needed for measuring disease diagnosis markers present at ultralow levels during early stages of disease progress. The emergence of metal-NPs is not only opening new scopes for highly sensitive bioaffinity and biocatalytic assays for novel biosensor and chemical sensors protocols but also leads to the excellent prospects for designing highly selective bioassays of various applications such as nucleic acids and proteins [2]. Voltammetric techniques are certainly the most widely employed methods in electrochemical analysis, including sensing applications based on metal, metal-oxide, semiconductor and composite metal NPs. In the subsequent sections, several examples of the use of voltammetric methods with NP detectors are described with the content being categorized according to the nanomaterial type. In the final part of this section, we give an overview of the other electrochemical methods that use metal-NP-based constructs as sensors.