Optical Detection of Ketoprofen by Its Electropolymerization on an Indium Tin Oxide-Coated Optical Fiber Probe

Abstract

In this work an application of optical fiber sensors for real-time optical monitoring of electrochemical deposition of ketoprofen during its anodic oxidation is discussed. The sensors were fabricated by reactive magnetron sputtering of indium tin oxide (ITO) on a 2.5 cm-long core of polymer-clad silica fibers. ITO tuned in optical properties and thickness allows for achieving a lossy-mode resonance (LMR) phenomenon and it can be simultaneously applied as an electrode in an electrochemical setup. The ITO-LMR electrode allows for optical monitoring of changes occurring at the electrode during electrochemical processing. The studies have shown that the ITO-LMR sensor’s spectral response strongly depends on electrochemical modification of its surface by ketoprofen. The effect can be applied for real-time detection of ketoprofen. The obtained sensitivities reached over 1400 nm/M (nm·mg−1·L) and 16,400 a.u./M (a.u.·mg−1·L) for resonance wavelength and transmission shifts, respectively. The proposed method is a valuable alternative for the analysis of ketoprofen within the concentration range of 0.25–250 μg mL−1, and allows for its determination at therapeutic and toxic levels. The proposed novel sensing approach provides a promising strategy for both optical and electrochemical detection of electrochemical modifications of ITO or its surface by various compounds.

Influence of indium tin oxide residues on the electrical performance of hydrogenated amorphous silicon thin-film transistors in the backplane of active-matrix displays

“…2d, and can be deconvoluted into two peaks O 1− or O 2 − and O 2− . The peak O 2− (binding energy (BE) = 529.6 eV), with an area ratio of 48%, is assigned to crystallized In 2 O 3 -like oxygen, 6 and the peak O 1− or O 2 − (BE = 531.3 eV), with an area ratio of about 52%, is ascribed to amorphous In 2 O 3 -like oxygen, 35 which is adjacent to oxygen deficiency sites. 36 Similar to O 1s in Fig.…”

A Comprehensive Review: Materials for the Fabrication of Optical Fiber Refractometers Based on Lossy Mode Resonance

“…Over the last decade, several sensors using ITO as the coating material for the generation of LMR have been studied. ITO has been used on multimode fibers of different diameters [7,19,20], as well as D-shaped fibers [16,21] or glass slide in Kretschmann configuration [22]. Most authors have studied ITO as a coating material by fabricating a thin film by means of sputtering [16,23,24] or thermal evaporation technique [7], however other techniques such as dip coating have also been used [19].…”

“…From another perspective, some authors have taken advantage of the electrical conductivity of ITO for the development of LMR-based electrochemical sensors using ITO-coated MMFs [20,24,30,31]. For instance, an optical ketoprofen sensor was reported by Smietana et al in [20]. This device monitored the electropolymerization of ketoprofen on an ITO coating showing, a LOD of 0.536 mM.…”

Study on Combined Optical and Electrochemical Analysis Using Indium‐tin‐oxide‐coated Optical Fiber Sensor

“…In our previous work we proposed a simple optical‐fiber‐based device where both optical and EC readouts are possible . Such a sensor may be used for optical monitoring of EC processes taking place on its surface . Unlike in other works employing ITO deposited on tip of optical fibers , here a 2–3 cm long cladding‐striped side surface of a multimode fiber core was coated.…”