Non-Enzymatic Electrochemical Sensors for Accurate and Accessible Uric Acid Detection

Abstract

Gout arthritis, a painful condition characterized by the accumulation of uric acid (UA) crystals in the joints, necessitates the development of efficient and accessible diagnostic methods. In this study, we present the design and fabrication of non-enzymatic electrochemical sensors based on molecularly imprinted conducting polymer nanostructures for the selective detection and monitoring of UA. To overcome the limitations of current point-of-care (POC) diagnostics, we developed a disposable voltammetric sensor capable of selectively and accurately analyzing UA concentrations at room temperature and pH 7.4. The sensor utilizes a selective polythiophene layer, deposited on disposable screen-printed electrodes, for the reversible binding and recognition of UA. Extensive electrochemical measurements employing electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry demonstrate excellent UA sensing performance in the wider concentration range of 1–500 μM using a standard redox solution with 2.91 µA/cm2·µM sensitivity, 354 nM detection limits, and substantial selectivity over common interferents. The sensor is capable of analyzing complex mixtures such as human saliva with 90.4% recovery of the spiked UA concentration. This highly sensitive and cost-efficient electrochemical sensor offers great promise for POC testing, disease monitoring, and predicting treatment outcomes related to gout arthritis.

Disposable Saliva Sensors for Early Cancer Diagnosis Using Hyper-Cross-Linked Molecularly Imprinted Polymeric Electrocatalysts

“…The sPMA2TA@g-C 3 N 4 sensor reveals the highest I pa values and better resolution of varying spermine concentrations, which is due to the synergic effect of spermine imprinting and assimilation of g-C 3 N 4 nanosheets with the imprinted polymeric matrix. This is also supported by the fact that a significantly lower R ct of the sPMA2TA@g-C 3 N 4 electrocatalytic layer improves charge transfer at the electrode–electrolyte interface . Surprisingly, the sPMA2TA sensor shows very little resolution between different concentrations of spermine, compared to the PMA2TA and PMA2TA@g-C 3 N 4 sensors.…”

“…This is also supported by the fact that a significantly lower R ct of the sPMA2TA@g-C 3 N 4 electrocatalytic layer improves charge transfer at the electrode−electrolyte interface. 30 Surprisingly, the sPMA2TA sensor shows very little resolution between different concentrations of spermine, compared to the PMA2TA and PMA2TA@g-C 3 N 4 sensors. This is attributed to the specific interactions between sPMA2TA and spermine, which lead to the chemisorption of the analyte on the surface of the electrode, thereby insulating the charge transfer at the electrode−electrolyte interface.…”

“…The human saliva samples were obtained from the members of the research team via passive drooling. The storage, pretreatment, and analysis conditions are described elsewhere . Briefly, the samples were first centrifuged to remove debris or food particles and then filtered through a 0.22 μm syringe filter to remove biomacromolecules, such as mucopolypeptides.…”

“…The storage, pretreatment, and analysis conditions are described elsewhere. 30 Briefly, the samples were first centrifuged to remove debris or food particles and then filtered through a 0.22 μm syringe filter to remove biomacromolecules, such as mucopolypeptides. The filtered saliva samples were diluted with the standard redox solution (in a volumetric ratio of 1:2) and stored at 8 °C before use.…”

Target-Imprinted Polyaniline/Nb2O5 Nanoparticles as Electrochemical Interfaces for Monitoring Kidney Function

“…The recovery (%) of spiked Cre concentrations is calculated according to the following formula: Recovery (%) = (C recovered /C spiked ) × 100; where C recovered = (C total − C initial ). 31,57 Three saliva samples, pure or spiked with 200, 600, and 1000 nM Cre concentrations, are tested, and the results are reported in Figure 6d−f. The Cre-PAni/Nb 2 O 5 sensors exhibit excellent recovery (94.3−99.9%) of the spiked Cre concentrations in saliva, with a mean value of 97.41 ± 2.83% (n = 3).…”