Voltammetric and amperometric techniques are powerful analytical tools that are widely used in chemical analysis. This article reviews a summary of some important types of modifying agents and their application in voltammetric and amperometric sensors for clinically and biologically important target species reported from the period 2003 to 2013. In this review, different modifiers such as molecularly imprinted polymers (MIPs), polymers, metal complexes, nanomaterials and composite films are discussed. Under the heading of each modifier, method of fabrication, properties, and applications of chemically modified electrodes (CMEs) are given. Tables that give analyte, modified electrode, measurement technique, measuring medium, linear detection range (LDR) and limit of detection (LOD) referenced from original work are also provided. © 2015, Pleiades Publishing, Ltd.