The use of biosensors in point‐of‐care (POC) testing devices has attracted considerable attention in the past few years, mainly because of their high specificity, portability, and relatively low cost. Coupling these devices with miniaturized electrochemical transducers has shown great potential toward simple, rapid, and cost‐effective analysis that can be performed in the field, especially for healthcare, environmental monitoring, and food quality control. For this reason, the number of publications in this field has grown exponentially over the past decade, making it a trending topic in current research. Although great improvement has been achieved in the field of electrochemical biosensing, there are still some challenges to overcome, especially concerning the improvement of sensing materials and miniaturization. In this Review, we summarize some of the most recent advances achieved in POC electrochemical biosensor applications, focusing on new materials and modifiers for biorecognition developed to improve sensitivity, specificity, stability, and response time.

Biological interfacing of graphene has become crucial to improve its biocompatibility,\ud dispersability, and selectivity. However, biofunctionalization of\ud graphene without yielding defects in its sp 2 -carbon lattice is a major challenge.\ud Here, a process is set out for biofunctionalized defect-free graphene\ud synthesis through the liquid phase ultrasonic exfoliation of raw graphitic\ud material assisted by the self-assembling fungal hydrophobin Vmh2. This\ud protein (extracted from the edible fungus Pleurotus ostreatus ) is endowed\ud with peculiar physicochemical properties, exceptional stability, and versatility.\ud The unique properties of Vmh2 and, above all, its superior hydrophobicity,\ud and stability allow us to obtain a highly concentrated (≈440–510 μg mL −1 ) and\ud stable exfoliated material ( ζ -potential, +40/+70 mV). In addition controlled\ud centrifugation enables the selection of biofunctionalized few-layer defect-free\ud micrographene fl akes, as assessed by Raman spectroscopy, atomic force\ud microscopy, scanning electron microscopy, and electrophoretic mobility.\ud This biofunctionalized product represents a high value added material for\ud the emerging applications of graphene in the biotechnological fi eld such as\ud sensing, nanomedicine, and bioelectronics technologies

A miniaturized, disposable, and low cost Ag/AgCl pseudoreference electrode based on inkjet printing has been developed. Silver ink was printed and chlorinated with bleach solution. The reference electrodes obtained in this work showed good reproducibility and stability during at least 30 min continuous measurement and even after 30 days storage without special care. Moreover, the strategy used in this work can be useful for large scale production of a solid-state Ag/AgCl pseudoreference electrode with different designs and sizes, facilitating the coupling with different electrical/electrochemical microsensors and biosensors.

In this work, a new hypothesis for the electrocatalytic behavior of CuO electrodes is presented. Different from the established mechanism, here we discuss why Cu species do not participate in the oxidation mechanism of carbohydrates. We show that hydroxyl ion adsorption and the semiconductive properties of the material play a more significant role in this process. The relationship between the flat band potential and the potential that begin oxidation suggests that the concentration of vacancies in the charge region acts upon the reactivity of the adsorbed hydroxyl ions through a partial charge transfer reaction. In the presence of carbohydrate molecules, the electron transfer is facilitated and involves the transfer of electrons from the adsorbed hydroxyl ions to the CuO film. This mechanism is fundamentally relevant since it helps the understanding of several experimental misleads. The results can also lead to obtaining better catalysts, since improvements in the material should focus on enhancing the semiconductive properties rather than the Cu/Cu redox transition. The results shed light on different aspects of carbohydrate molecules oxidation that could lead to novel applications and possibly a better description of other semiconductor mechanisms in electrocatalysis.