In this work, we propose a novel functionalized carbon nanotube (f-CNT) supporting nanoporous cauliflower-like Pd nanostructures (PdNS) as an enzyme-free interface for glucose electrooxidation reaction (GOR) in a neutral medium (pH 7.4). The novelty resides in preparing the PdNS/f-CNT biomimetic nanocatalyst using a cost-effective and straightforward method, which consists of drop-casting well-dispersed f-CNTs over the Screen-printed carbon electrode (SPCE) surface, followed by the electrodeposition of PdNS. Several parameters affecting the morphology, structure, and catalytic properties toward the GOR of the PdNS catalyst, such as the PdCl₂ precursor concentration and electrodeposition conditions, were investigated during this work. The electrochemical behavior of the PdNS/f-CNT/SPCE toward GOR was investigated through Cyclic Voltammetry (CV), Linear Sweep Voltammetry (LSV), and amperometry. There was also a good correlation between the morphology, structure, and electrocatalytic activity of the PdNS electrocatalyst. Furthermore, the LSV response and potential-pH diagram for the palladium–water system have enabled the proposal for a mechanism of this GOR. The proposed mechanism would be beneficial, as the basis, to achieve the highest catalytic activity by selecting the suitable potential range. Under the optimal conditions, the PdNS/f-CNT/SPCE-based biomimetic sensor presented a wide linear range (1–41 mM) with a sensitivity of 9.3 µA cm⁻² mM⁻¹ and a detection limit of 95 µM (S/N = 3) toward glucose at a detection potential of +300 mV vs. a saturated calomel electrode. Furthermore, because of the fascinating features such as fast response, low cost, reusability, and poison-free characteristics, the as-proposed electrocatalyst could be of great interest in both detection systems (glucose sensors) and direct glucose fuel cells.

This research sought to enhance the efficiency and biocompatibility of anodes in bioelectrochemical systems (BESs) such as microbial fuel cells (MFCs), with an aim toward large-scale, real-world applications. The study focused on the effects of acid-heat treatment and chemical modification of three-dimensional porous pristine carbon felt (CF) on power generation. Different treatments were applied to the pristine CF, including coating with carbon nanofibers (CNFs) dispersed using dodecylbenzene sulfonate (SDBS) surfactant and biopolymer chitosan (CS). These processes were expected to improve the hydrophilicity, reduce the internal resistance, and increase the electrochemically active surface area of CF anodes. A high-resolution scanning electron microscopy (HR-SEM) analysis confirmed successful CNF coating. An electrochemical analysis showed improved conductivity and charge transfer toward [Fe(CN)6]^3−/4− redox probe with treated anodes. When used in an air cathode single-chamber MFC system, the untreated CF facilitated quicker electroactive biofilm growth and reached a maximum power output density of 3.4 W m⁻², with an open-circuit potential of 550 mV. Despite a reduction in charge transfer resistance (R_ct) with the treated CF anodes, the power densities remained unchanged. These results suggest that untreated CF anodes could be most promising for enhancing power output in BESs, offering a cost-effective solution for large-scale MFC applications.

This work reports on the development, and preliminary results of a multiphysics probe for deep brain monitoring of neurotransmitters and metabolites in the glioblastoma environment. We made the proof of the concept of our probe with common mice glioblastoma cells GL261 modified with Green Fluorescent Protein. A silicon probe with a platinum electrode at the tip was functionalized with an enzyme in order to detect, for example, Glucose, D-serine, Lactate or Glutamate. In addition, an optical fiber was inserted in a groove in the middle of the probe for light excitation and detection of glioblastoma cells by fluorescence.

Brain tissue oxygen pressure (PbtO2) monitoring is important to understand brain metabolism at rest or during neuronal activation. Electrochemistry provides high spatial and temporal resolution to achieve PbtO2 monitoring, especially platinum (so-called Clark electrodes) and carbon fiber microelectrodes (CFMEs). However, a major problem with in vivo PbtO2 recordings is a significant loss of sensitivity due to sensor fouling in the living brain tissue. Here, we tested a polyphenylenediamine-polyurethane (PPD-PU) coating to minimize electrode fouling in vivo and improve the stability of PbtO2 recordings. PPD and PU coatings were deposited on CFMEs (7 μm diameter, 100 μm long, 4400 μm2) and displayed less fouling in vivo than bare CFMEs, or CFMEs coated with PPD only. Oxygen reduction started around -300 mV vs Ag/AgCl and PPD-PU deposition increased microelectrode diameter by 1-2 μm. Carbon fiber microelectrodes coated with PPD-PU were used for 2.5-5 h of PbtO2 monitoring in anesthetized rats and there was no significant change in O2 sensitivity before and after in vivo implantation. These results indicate that PbtO2 monitoring can be achieved reliably using PPD-PU coating on carbon fiber microelectrodes, preventing electrode fouling in vivo, and providing an inexpensive and minimally invasive tool to study brain oxygen metabolism.