Electrochemical aptasensor for detection of ractopamine

Abstract

Ractopamine is a compound of β-agonists group. Β-receptor agonists are often used as an agent for the prevention and treatment of asthma and exercise-induced shortness of breath. Also, due to their anabolic effects they can lead to an increase in skeletal muscle mass and cause abuse of these compounds. Goal: In this research work, an aptasensor based on multiple amplification of the signals was designed with the aid of multi-layer nanocomposites to detect Ractopamine. Methods and materials: A polymeric layer of graphene quantom dots (GQDs) and chitosan functionalized graphene quantom dot (GQD-CS) was deposited on glassy carbon electrode. After activation of the electrode surface, gold nano particles were deposited on the surface of pre-modified GCE. In the following, Aptamer as a bioreceptor was immobilized on modified glassy carbon electrode and after blocking the non-specicific sites of the electrode surface, designed aptasensor is used to determine the amount of Ractopamine in the standard samples and also in human plasma sample. Result: Under optimum conditions, aptasensor is able to determine the amount of Ractopamine in a linear range of 0.0044 femtomolar to 19.5 micromolar. Discusssion: An ultra-sensitive aptasensor was designed to determine low concentration of ractopamine in standard samples as well as human plasma samples. Considering the unique features of aptasensor such as stable immobilization of the aptamer on a new type of substrate (chitosan functionalized graphene quantom dot / gold nano particles), the capability towards determination low concentrations of drug in femtomolar range, this sensor can be used in clinical models.