Gold–deferrioxamine nanometric interface for selective recognition of Fe(III) using square wave voltammetry and electrochemical impedance spectroscopy methods

A Simple Small Size and Low Cost Sensor Based on Surface Plasmon Resonance for Selective Detection of Fe(III)

“…The detection limit is relatively high, compared with that claimed by applying other transduction methods [27] and with the concentration levels actually found in real life samples. Evidently the conditional constant for the combination of Fe(III) with DFO in the SAM at relatively acidic pH is not high enough to make possible the combination of a sufficient amount of Fe(III) to give an optical signal (resonance wavelength shift) significantly different from the noise, when the Fe(III) concentration is lower than 2 × 10 −6 M. Work is in progress to improve the sensitivity of the method, for example by modifying the geometry of the optical fiber, as suggested in a previous investigation [16].…”

“…The complexation of Fe(III) by DFO in solution is strong even at this high acidity [26], as it is in the case of DFO covalently linked to a solid phase (silica) [6]. The fact that Fe(III) is able to interact with the DFO-SAM-POF here considered has been shown by Shervedani et al [3,27] by electrochemical detection. In the present investigation we would like to demonstrate that the association of Fe(III) with the DFO in the monolayer is able to produce an optical signal, due to a refractive index change, despite of the low mass of the substance interacting with the sensor surface (the atomic mass of Fe(III) is only 55.845 amu).…”

“…A large number of anions and cations have been previously examined by Shervedani et al [27] by an electrochemical sensor based on the same DFO-SAM, for their possible interference in Fe(III) determination. It has been found that the majority of the ions interfere only at very high concentrations.…”

“…It relies on a strong ligand, DFO, which has been covalently linked to a gold surface as a self-assembled monolayer, according to a previously reported method [3,27]. A useful optical response, ascribable to the Fe(III)-DFO interaction on the solid surface of the sensor, has been obtained, despite the low mass of the considered metal ion.…”

An overview of Structured Biosensors for Metal Ions Determination

“…When complexation is the main principle involved, the temperature was generally not controlled. In rare exceptions, an acidic pH between 1 and 2 was exploited for biosensing [54,[65][66][67][68]]. An alkaline pH was not evaluated due to the decrease in biochemical responses and to the hydrolysis of metal ions.…”