Cellulose microfluidic pH boosting on copper oxide non-enzymatic glucose sensor strip for neutral pH samples

Biofouling-resistant nanomaterials for non-enzymatic glucose sensors: A critical review

Biofouling is a significant concern in sensors and diagnostic applications as it results in reduced sensitivity, selectivity, and response time, false signals or noise, and ultimately causes a reduction in the sensor lifespan. This is particularly a concern while developing non-enzymatic glucose sensors (NEGS) that can be used to fabricate implantable sensors for continuous glucose monitoring. Thus, developing advanced materials solutions in the form of nanomaterials that display inherent antifouling activity is imperative. Due to their small nanosized dimensions and tunable microstructures, nanomaterials display unique physio-chemical properties that display antifouling efficiency and thus can be applied towards developing highly stable, sensitive, and selective NEGS. Through this review, we aim to explore the recent advances in the field of antifouling nanomaterials that offer promising potential to be applied towards developing NEGS. We discuss the details of various biofouling-resistant nanomaterials, including graphene and graphene oxide, carbon nanotubes, gold nanoparticles, silver nanoparticles, metal oxide nanoparticles, and polymeric nanocomposites. Further, we highlighted the possible mechanism of action involving nanomaterials in providing antifouling features in NEGS, followed by a brief discussion of the advantages and disadvantages of using nanomaterials for antifouling in developing NEGS. Finally, we concluded the article by proposing the future prospects of this promising technology.

A core-shell AZO@ZnO nanostructure for accurate glucose detection with UV-boosted sensitivity

Advances in micro-nano fabrication technology have enabled flexible electrochemical sensors to utilize micro-nanostructures and nanomaterials. Herein, a 3D AZO@ZnONRs core-shell nanostructure was synthesized using atomic layer deposition and hydrothermal techniques. The structure was employed to fabricate a high-sensitivity glucose sensor capable of precise detection of blood glucose levels and glucose content in sugary beverages. The sensor demonstrated a highly linear response (0-12.5 mM), with a sensitivity of approximately 6.49 µA·mM-1·cm-2 and a detection limit of 1.561 µM. Under ultraviolet light, the sensitivity increased by 1.83-fold. In the presence of interferents such as potassium chloride, sodium chloride, lactic acid, urea, and uric acid, the sensor maintained excellent specificity. Compared to conventional nanorods, this 3D core-shell material preserved the advantages of a high specific surface area while demonstrating enhanced electron transfer capabilities and photosensitivity, enabling reliable detection of glucose at extremely low concentrations. This study systematically analyzed the characteristics of the core-shell nanomaterial and its photocatalytic mechanisms, advancing photocatalytic electrochemical sensing technology.

Rapid determination of toxic and essential metal binding proteins in biological samples by size exclusion chromatography-inductively coupled plasma tandem mass spectrometry

Metalloproteins binding with trace elements play a crucial role in biological processes and on the contrary, those binding with exogenous heavy metals have adverse effects. However, the methods for rapid, high sensitivity and simultaneous analysis of these metalloproteins are still lacking. In this study, a fast method for simultaneously determination of both essential and toxic metal-containing proteins was developed by coupling size exclusion chromatography (SEC) with inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). After optimization of the separation and detection conditions, seven metalloproteins with different molecular weight (from 16.0 to 443.0 kDa) were successfully separated within 10 min and the proteins containing iron (Fe), copper (Cu), zinc (Zn), iodine (I) and lead (Pb) elements could be simultaneously detected with the use of oxygen as the collision gas in ICP-MS/MS. Accordingly, the linear relationship between log molecular weight and retention time was established to estimate the molecular weight of unknown proteins. Thus, the trace metal and toxic metal containing proteins could be detected in a single run with high sensitivity (detection limits in the range of 0.0020-2.5 μg/mL) and good repeatability (relative standard deviations lower than 4.5 %). This method was then successfully used to analyze metal (e.g., Pb, Zn, Cu and Fe) binding proteins in the blood of Pb-intoxicated patients, and the results showed a negative correlation between the contents of zinc and lead binding proteins, which was identified to contain hemoglobin subunit. In summary, this work provided a rapid and sensitive tool for screening metal containing proteins in large number of biological samples.

Optimized Copper-Based Microfeathers for Glucose Detection

Diabetes is expected to rise substantially by 2045, prompting extensive research into accessible glucose electrochemical sensors, especially those based on non-enzymatic materials. In this context, advancing the knowledge of stable metal-based compounds as alternatives to non-enzymatic sensors becomes a scientific challenge. Nonetheless, these materials have encountered difficulties in maintaining stable responses under physiological conditions. This work aims to advance knowledge related to the synthesis and characterization of copper-based electrodes for glucose detection. The microelectrode presented here exhibits a wide linear range and a sensitivity of 1009 µA∙cm-2∙mM-1, overperfoming the results reported in literature so far. This electrode material has also demonstrated outstanding results in terms of reproducibility, repeatability, and stability, thereby meeting ISO 15197:2015 standards. Our study guides future research on next-generation sensors that combine copper with other materials to enhance activity in neutral media.