Open AccessMelanin as an active layer in biosensors
Author(s) -
Marina PiacentiSilva,
Jéssica Colnaghi Fernandes,
Natália Biziak de Figueiredo,
Mirko Congiu,
Marcelo Mulato,
Carlos F. O. Graeff
Publication year - 2014
Publication title -
aip advances
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.421
H-Index - 58
ISSN - 2158-3226
DOI - 10.1063/1.4869638
Subject(s) - biosensor , indium tin oxide , substrate (aquarium) , dielectric spectroscopy , melanin , thin film , materials science , layer (electronics) , chemistry , nanotechnology , analytical chemistry (journal) , chemical engineering , electrochemistry , electrode , organic chemistry , oceanography , biochemistry , engineering , geology
The development of pH sensors is of great interest due to its extensive application in several areas such as industrial processes, biochemistry and particularly medical diagnostics. In this study, the pH sensing properties of an extended gate field effect transistor (EGFET) based on melanin thin films as active layer are investigated and the physical mechanisms related to the device operation are discussed. Thin films were produced from different melanin precursors on indium tin oxide (ITO) and gold substrates and were investigated by Atomic Force Microscopy and Electrochemical Impedance Spectroscopy. Experiments were performed in the pH range from 2 to 12. EGFETs with melanin deposited on ITO and on gold substrates showed sensitivities ranging from 31.3 mV/pH to 48.9 mV/pH, depending on the melanin precursor and the substrate used. The pH detection is associated with specific binding sites in its structure, hydroxyl groups and quinone imine. (C) 2014 Author(s)
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom