Electrochemical sensors based on conducting polymers for organic molecules detection

Organic molecules such as neurotransmitters and uric acid have a fundamental role in the human body function regulation. Therefore, the detection and quantification of those molecules in human fluid have a pharmaceutical and therapeutically relevance. In that context, the electrochemical sensors appear as a low cost, rapid, easy to use and in situ application option for determination of organic molecules in liquid solution. Conducting polymers (CPs) are very explored sensor building materials because its high electrical conductivity, versatility, multiple synthesis pathways and stability in environmental conditions. This document presents a state-of-the-art review of the most relevant research about electrochemical sensors based on conducting polymers and their application in the determination of dopamine, epinephrine, serotonin and uric acid. An analysis of the synthetic process and morphological characterization was carried out, highlighting the different types of micro and nano structures, generated for the polymer itself or the combination with different materials in a composite. Furthermore, the performance and ability to detect traces of previous mentioned molecules by CPs based sensors is compared. These analyzes were performed using the sensitivity and the limit of detection (LOD) as parameters, and it was also evaluated how the mesoporosity, microporosity and roughness of the electrode surface affect these figures of merit. This bibliographic review considers the scientific publications made from 2015 to 2020; where polypyrrole (PPy), polyaniline (PANI) and poly (3,4-ethylenedioxythiophene (PEDOT) appear as the most recurrent CPs for the construction of electrochemical sensors.