Powerful Electron-Transfer Screen-Printed Platforms as Biosensing Tools: The Case of Uric Acid Biosensor.

Rocco Cancelliere,Laura Micheli,Antonino Cataldo,Stefano Bellucci,Alessio Di Tinno

doi:10.3390/bios12010002

Rocco Cancelliere, Laura Micheli + Show 3 more

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https://doi.org/10.3390/bios12010002

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Abstract

The use of carbon nanomaterials (CNMs) in sensors and biosensor realization is one of the hottest topics today in analytical chemistry. In this work, a comparative in-depth study, exploiting different nanomaterial (MWNT-CO2H, -NH2, -OH and GNP) modified screen-printed electrodes (SPEs), is reported. In particular, the sensitivity, the heterogeneous electron transfer constant (k0), and the peak-to-peak separation (ΔE) have been calculated and analyzed. After which, an electrochemical amperometric sensor capable of determining uric acid (UA), based on the nano-modified platforms previously characterized, is presented. The disposable UA biosensor, fabricated modifying working electrode (WE) with Prussian Blue (PB), carbon nanotubes, and uricase enzyme, showed remarkable analytical performances toward UA with high sensitivity (CO2H 418 μA μM−1 cm−2 and bare SPE-based biosensor, 33 μA μM−1 cm−2), low detection limits (CO2H 0.5 nM and bare SPE-based biosensors, 280 nM), and good repeatability (CO2H and bare SPE-based biosensors, 5% and 10%, respectively). Moreover, the reproducibility (RSD%) of these platforms in tests conducted for UA determination in buffer and urine samples results are equal to 6% and 15%, respectively. These results demonstrate that the nanoengineered electrode exhibited good selectivity and sensitivity toward UA even in the presence of interfering species, thus paving the way for its application in other bio-fluids such as simple point-of-care (POC) devices.

Highlights

Critical importance in electroanalytical measurement is given to the magnitude of the electrochemical response and its reproducibility
The comparison with the surface of carbon nanomaterials (CNMs)-modified screen-printed electrodes (SPEs) highlights that the nanostructures retraced the underlying graphite particles and increased the surface area of working electrodes: the nanomaterials are not coated by the polymer matrix of the conductive inks, and this factor helps dramatically to enhance the surface area
cyclic voltammetry (CV), allowing us to understand and explain the chemistry related to the different functionalization of the CNMs employed in SPE construction, undertook a quantitative characterization study of electron transfer processes at the diverse CNMs-modified interfaces

Summary

Introduction

Critical importance in electroanalytical measurement is given to the magnitude of the electrochemical response and its reproducibility. In the field of electrochemistry, the parameter that fully describes the aforementioned process is the heterogeneous electron transfer constant (k0). The extensive comprehension of this electrochemical feature, along with the growing demand for super-sensitive and reliable electrochemical sensors, have paved the way, over the last decade, for the development and applications of innovative technologies and materials. In this overall scenario, some works dealing with electrochemical sensors based on nanomaterials-modified platforms are frequently reported in the literature [4,5,6]. The electrochemical field benefits from the enhanced electrochemical performances of these materials (e.g., sensitivity, stability, selectivity) applied in the modification of electrodic platforms

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