Abstract
Enzymes, primarily different types of oxidases and most commonly peroxidase, are often used in the construction of biosensors. Enzymatic biosensors, due to their small size, easy to handle construction, accuracy and specificity, are powerful healthcare tools commonly used for the diagnosis of diseases for more than 20 years. Unfortunately, the loss of enzymatic activity during the immobilization of enzymes into biosensors has been a recent major problem. Hence, nonenzymatic electrochemical sensors based on organic and inorganic nanostructures have gained great attention in the last few years. In this short review, different types of nanostructures and nanocomposites and their practical applications in the construction of nonenzymatic electrochemical sensors in healthcare and diagnosis are described and summarized.