Smart nano-actuators for electrochemical sensing of Metformin in human plasma

Smart artificial nano-actuators were developed using electroactive acrylamide polymer nanoparticles by molecular imprinting. These nanoparticles are receptors that mimic the specificity of antibodies and replace enzymes in traditional biosensors allowing highly sensitive and selective monitoring. Electroactive polymer nanoparticles can be synthesized by the including of ferrocene, which confers signaling functions. These actuators operate by a swelling mechanism in response to a specific electrochemical stimulus. Molecular recognition is based on molecular imprinting and binding of the target molecule. The polymer nanoparticles were computationally designed to bind to Metformin and synthesized by controlled free-radical polymerization. Polymer nanoparticles were incorporated on the surface using screen-printed electrodes. As a result, these nano-actuators allow extremely sensitive monitoring of Metformin in human plasma. Metformin is essential for treating various chronic diseases, and monitoring is necessary to reduce collateral drug side effects. Herein, sensing of Metformin was achieved by differential pulse voltammetry (DPV) in a concentration range between 100 and 2000 pM, with a limit of detection of 9 pM and sensitivity at 31.5 nA pM−1 (0.998) in plasma. No cross-reactivity was observed against potential interferences (Sitagliptin and Paracetamol). This technology can be potentially applied for rapid point-of-care testing as an alternative to laboratory-based techniques, reducing the time and cost of the analysis.