Fabrication of electrochemical /photoelectrochemical biosensor using novel nano materials

ASIANALYSIS XIII 8–11 December 2016, Chiang Mai, THAILAND Fabrication of electrochemical /photoelectrochemical biosensor using novel nano materials A. Gopalan, N. Muthuchamy,, K-P. Lee Department of Chemistry Education, Kyungpook National University, Republic of Korea, Research Institute of Advanced Energy Technology, Kyungpook National University, Republic of Korea, Department of Nanoscience and Nanotechnology, Kyungpook National University, Republic of Korea. E-mail: [email protected] Sensors based on electrochemical methods posses advantages such as portability, low cost, short analysis time and excellent sensitivity Also, photoelectrochemical sensor is a new kind of developing analytical device based on the photoelectrochemical properties of materials. Because of its remarkable sensitivity, inherent miniaturization, portability and easy integration, photoelectrochemical analysis is becoming a promising analytical technique. In recent years, carbon nanomaterials such as carbon nanotubes(CNT), graphene(G), and nanodiamonds (ND), plasmonic nanoparticles such as gold (Au) nanostructures etc. have been extensively utilized, in their pristine and functionalized forms, toward sensor applications. Importantly, these nanomaterials can be suitably modified to generate sensing probes for few of the analytes. This lecture focuses our research activities on the development of few novel nanomaterials towards fabrication of electrochemical/photeoelectrochemical sensors.(1-4) Polyaniline chains were grafted onto nanodiamond (PANI-g-ND) through electrochemical polymerization of aniline in the presence of amine functionalized ND. A robust and effective composite film comprising PANI-g-ND/gold particles was subsequently prepared. Cyclic voltammograms revealed that PANI-g-ND/Au/cyt c exhibited an excellent electrocatalysis towards the detection of nitrite ions. Differential pulse voltammetry of PANI-g-ND/Au/cyt c revealed a wide linear concentration range (0.5 μM-3 mM) for current responses, sensitivity (88.2 μA/mM) and low detection limit (0.16 μM) towards the electrochemical detection of nitrite ions. We demonstrate the use of a novel CP-based MCNB, comprising a functionalized CP, Fc, and Cu NP for efficient NEG sensing. We have chosen poly(aniline-co-anthranilic acid)-grafted G sheets [designated as G-PANI(COOH)] as the parent CP, and branched polyethyleneimine (b-PEI) as the cross-linking polymer, ferrocene carboxyaldehyde (Fc-CHO) as the cross-linker, and Cu NPs for the preparation of the new MCNB. The components GPANI(COOH), b-PEI, and Fc-CHO were integrated to form a cross-linked network structure, and further dispersed with the Cu NPs to obtain G-PANI(COOH)-PEI-Fc/Cu-MCNB. Electrochemical measurements showed that the G-PANI(COOH)-PEI-Fc/Cu-MCNB/GCE modified electrode exhibited good electrocatalytic behavior towards the detection of glucose in a wide linear range (0.50 to 15 mM), with a low detection limit (0.16 mM) and high sensitivity (14.3 μA mM cm). We reported the fabrication of a novel electrochemical-PEC dual mode biosensor utilizing the beneficial components such as G, TiO2(G)-NWs and CS and transforming them into a NS through establishment of chemical interactions between modified TiO2-NWs and G. We designated the assemblies of G and TiO2(G)-NWs as G/Ti(G)-3DNS. The G/Ti(G)-3DNS was further modified with CS and used for immobilization of ChOx to fabricate the biosensor G/Ti(G)-3DNS/CS/ChOx and used as the electrochemical-PEC dual mode biosensor for the detection of cholesterol. The G/Ti(G) 3DNS/CS/ChOx bioelectrode was selective to cholesterol with a remarkable sensitivity (3.82 μA/cm mM) and a lower detection limit (6 μM). Also, G/Ti(G) 3DNS/CS/ChOx functioned as photoelectrode and exhibited selective detection of cholesterol under a low bias voltage and light irradiation. We are pursuing continuous research for exploring the various kind of nanomaterials for sensing application.