Development and characterization of NPs-modified carbon electrodes obtained by pyrolysis of paper strips

FAUSTO N. COMBA; TOMÁS E. BENAVIDEZ; ANA M. BARUZZI; CARLOS D. GARCIA

Buenos Aires

Workshop; II Workshop on Electrochemical Devices - II Workshop Electrobionet; 2017

Metallic NPs-modified carbon electrodes (ECPNps) were obtained by pyrolysis of Whatman type 4 filter paper (96 g/m2) pre-soaked in 0.1 mol·L-1 metal transition salt (CuSO4, Cu(Ac)2, AgNO3, Co(Ac)2, CoCl2, and Pt(C2H8N2)2) solutions. The pyrolysis was performed under reducing atmosphere (H2, 5 % / Ar, 95 %) at 1000 °C for 1 hour. Carbon Electrodes were characterized by measuring the resistance (Ω) of the samples using a multimeter in order to calculate the resistivity (Ω·cm) of the modified carbon materials. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), and Raman spectroscopy were used to confirm the presence and distribution of metallic NPs after pyrolysis as well as the microstructure of the resulting carbonized samples. Furthermore, electrochemical techniques (cyclic voltammetry and amperometry) were performed to study the electrochemical activity of the ECPNps toward the H2O2 reduction.Centred on the promising electrocatalytic activity of metallic nanoparticles on the H2O2 reduction, the modified carbon electrodes were used as substrates for the design of glucose, lactic acid and serine biosensors. The ECPNps were then used as amperometric transducer for biosensors by immobilizing the corresponding oxidases (GOx, LOx, and DAOx). The analytical signal was the reduction of the hydrogen peroxide produced during the step of oxidase regeneration. Besides being a simple and inexpensive process for the development of electrocatalytic amperometric transducers for biosensing applications, this approach opens new possibilities for the in-situ synthesis of metallic nanoparticles without the traditional requirements of solutions and adjuvants present in the classical chemical synthesis.