**4.4 Electrochemical sensors**

Recently, research has focused on the utilization of NDs to construct new electrochemical nerves for applications like as drug detection, gas monitoring, genetic sequence diagnostics, etc. The high level of electrochemical reaction accuracy, photo-stability and resolution is one of the most important parameters in any sensory system. NDs are a good choice for the sensitivity of electrochemicals because of have unique features, such as durability, chemical resistance, biocompatibility, spin break, fluorescence, and catalytic structures [31]. Different conversion approaches have been developed to improve the sensory function of NDs, including turning NDs into self-assembled monolayers, oxygen plasmas, liquid chemical procedures, metal catalysis and so on. Modified NDs provide optimal melting, as well as special binding to targeted sensory analysts. Using square-wave voltammetry, a sensor (electrochemical) based on scattered Nanodiamonds with glassy carbon electrode (GCE) was reported on pyrazinamide (PZA) sensors [32]. In a typical way, carbon black nanoparticles modified-NDs are constructed to monitor based electrochemical transmitter using cyclic voltammetry, which produces a dopamine sensor with a detection limit of 0.06 mM [33].
