Biosensors

Monitoring uric acid (UA) concentration is crucial for human health, enabling early detection and prevention of metabolic disorders as well as assessing renal function and overall metabolic balance. Herein, we developed a field-effect transistor (FET)-based UA biosensor using hydrothermally synthesized vertical zinc oxide (ZnO) nanorods (NRs) and uricase. The fabricated FET biosensor was tested in phosphate-buffered saline (PBS) at increasing UA concentrations to evaluate its biosensing performance. The FET biosensor yields a sensitivity of 12.45 μA·mM⁻¹·cm⁻², covering a dynamic range of 0.05–2.75 mM. The calculated detection limit was ~0.0043 mM. The improved sensing performance results in a substantial enhancement of both detection sensitivity and limit of detection compared to the traditional lateral electrode setup. Additionally, selectivity, storage stability, fabrication reproducibility, and applicability for serum UA detection were evaluated. Overall, the vertical electrode configuration of the UA biosensor has the potential to be further extended for the sensitive detection of additional biomarkers.

In the original publication [...]

Cobalt–ruthenium bypiridine–oxalate metal–organic frameworks (MOFs) were synthesized via a solvothermal method with a custom-designed reactor that permits stirring, which can result in changes in the morphology of the structures. In this work, we performed a morphological and structural study of MOFs with varying tris(2,2,bipyridyl) and diclororuthenium(II) hexahydrate ${\left(Ru\right(bpy)}_3^{2+})$ concentrations, demonstrating changes in the size of the MOFs, and these MOFs were used as the luminescent materials in an electrochemiluminescent (ECL) system for glyphosate (Gly) detection, which acts as a coreactant in the light emission of ${Ru\left(bpy\right)}_3^{2+}$. Gly is the most commonly used herbicide worldwide, and our system has a calibration curve range of 10–70 ppm, with a detection limit of 7.6 ppm.