Abstract
In its ionic form, copper is a potentially toxic substance, thus, there is a need for developing a sensor to detect low levels of copper in environmental samples.
A new capacitive biosensor sensitive to copper(II) was developed. This was achieved by the deposition of the new synthesized ionophore 4‐phenyl‐4‐sulfide‐11‐(1‐oxodecyl)‐1,7‐dithia‐11‐aza‐4‐phosphacyclotetradecane using the Langmuir‐Blodgett (LB) technique. The LB films formed on the Si3N4/SiO2/Si substrate were characterized using X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and electrochemical impedance spectroscopy (EIS). The shift of the admittance curves owing to the variation of the Cu2+ concentration shows that the device is sensitive to this ion.
This work was supported by MEC under project grants TEC2004‐06514‐C03‐02/03, CTQ2004‐08046‐C02, NAN2004‐09415‐C05‐01, PCI 76/03‐04, HF2005‐0055, and TEC2005‐07996‐C02‐02 and by Generalitat de Catalunya trough project 2002PIRA 00167. Dr. A. Errachid acknowledges support from the “Ramón y Cajal” program. The authors wish to express their gratitude for the support received from Dr. Chris Mills in many discussions about this work.