A graphene/Si Schottky diode for the highly sensitive detection of protein

Continuous monitoring of molecular biomarkers in microfluidic devices

The ability to monitor molecular targets is crucial in fields ranging from healthcare to industrial processing to environmental protection. Devices employing biomolecules to achieve this goal are called biosensors. Over the last half century researchers have developed dozens of different biosensor approaches. In this chapter we analyze recent advances in the biosensing field aiming at adapting these to the problem of continuous molecular monitoring in complex sample streams, and how the merging of these sensors with lab-on-a-chip technologies would be beneficial to both. To do so we discuss (1) the components that comprise a biosensor, (2) the challenges associated with continuous molecular monitoring in complex sample streams, (3) how different sensing strategies deal with (or fail to deal with) these challenges, and (4) the implementation of these technologies into lab-on-a-chip architectures.

Hierarchical cage-frame type nanostructure of CeO2 for bio sensing applications: from glucose to protein detection

Self-assembled hierarchical nanostructures are slowly superseding their conventional counterparts for use in biosensors. These morphologies show high surface area with tunable porosity and packing density. Modulating the interfacial interactions and subsequent particle assembly occurring at the water-and-oil interface in inverse miniemulsions, are amongst the best strategies to stabilize various type of hollow nanostructures. The paper presents a successful protocol to obtain CeO₂ hollow structures based biosensors that are useful for glucose to protein sensing. The fabricated glucose sensor is able to deliver high sensitivity (0.495 μA cm^-2 nM^-1), low detection limit (6.46 nM) and wide linear range (0 nM to 600 nM). CeO₂ based bioelectrode can also be considered as a suitable candidate for protein sensors. It can detect protein concentrations varying from 0 to 30 µM, which is similar or higher than most reports in the literature. The limit of detection (LOD) for protein was ∼0.04 µM. Therefore, the hollow CeO₂ electrodes, with excellent reproducibility, stability and repeatability, open a new area of application for cage-frame type particles.