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

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.

Uricase Crowding via Polyelectrolyte Layers Coacervation for Carbon Fiber-Based Electrochemical Detection of Uric Acid

“…The obtained linear range, sensitivity, limit of detection, and Michaelis–Menten constant values of the fabricated sensor show its competitiveness with analogous enzymatic uric acid electrochemical sensors based on screen-printed electrodes or metal substrates [ 29 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ], the main characteristics of which are listed in Table 2 , as well as non-enzymatic sensors [ 56 ]. Unfortunately, sensor performance data for the electrodes modified with polyelectrolyte multilayers with alternating uricase layers [ 54 ] were insufficient for a direct comparison with the sensor in this work, but our fabricated sensor benefits from a lower consumption of uricase enzyme (one layer in this work vs. ten layers in [ 54 ]) and a less expensive substrate (CFE vs. Pt).…”

A non-enzymatic electrochemical sensor composed of nano-berry shaped cobalt oxide nanostructures on a glassy carbon electrode for uric acid detection

“…Mainly, enzyme-based electrochemical biosensors have been widely fabricated and studied, which offer remarkable selectivity and sensitivity. 10–15 Notably, the use of enzymes in biosensors results in limited storage stability and involves a complicated procedure for enzyme immobilization. Compared to enzymatic biosensors, the non-enzymatic sensors have more significant advantages of long-term storage stability and easy fabrication steps.…”

Sensitive Detection of Industrial Pollutants Using Modified Electrochemical Platforms

“…Herein, a facile and one-step-prepared sensor based on Carbon Nano-Materials (CNMs)-modified screen-printed electrodes (SPEs) is reported. It is well-known that the conventional SPEs (i.e., graphite, carbon) have serious issues due to their sluggish surface kinetics, which severely affects the sensitivity (i.e., broad peak, high potential needed, no peak at a lower concentration) and selectivity of the platforms [ 56 , 57 ]. Nowadays, CNMs represent the most valid solution to overcome this problem, owing to the wide range of applications and their physical and chemical properties [ 58 , 59 , 60 ].…”

“…Nowadays, CNMs represent the most valid solution to overcome this problem, owing to the wide range of applications and their physical and chemical properties [ 58 , 59 , 60 ]. Among the several advantages provided by the modification of SPEs with CNMs, the improved surface kinetics, the enhanced electroactive surface area, and the amended adsorption and functionalization capability are the most important [ 56 , 61 , 62 ]. Herein, we decided to use CNMs for the development of model sensors for the rapid, sensitive, and highly reproducible environmental monitoring of HQ and BQ.…”