Chronic microsensors for longitudinal, subsecond dopamine detection in behaving animals

Neurotransmission operates on a millisecond timescale but is changed by normal experience or neuropathology over days to months. Despite the importance of long-term neurotransmitter dynamics, no technique exists to track these changes in a subject from day to day over extended periods of time. Here we describe and characterize a microsensor that can detect the neurotransmitter dopamine with subsecond temporal resolution over months in vivo in rats and mice

Smart synthesis of hollow core mesoporous shell carbons (HCMSC) as effective catalyst supports for methanol oxidation and oxygen reduction reactions

The present paper describes an easy and quick synthesis of hollow core mesoporous shell carbon (HCMSC) simply templated from unpretreated solid core mesoporous shell silica using a cheap precursor like sucrose. Physical characterizations showed uniform spherical carbon capsules with a hollow macroporous core of ca. 305- and 55-nm-thick mesoporous shell, forming a well-developed 3-D interconnected bimodal porosity. High specific surface area and large pore volume were also confirmed, suggesting the obtained HCMSC as a promising catalyst support. HCMSC-supported Pt (nominal 20 wt.%) with an average Pt particle size of 1.9 nm was synthesized by wet impreg-nation, and a signal of strong interaction between carbon support and platinum was confirmed by X-ray photoelectron spectroscopy. In cyclic voltammetry and linear sweep vol-tammetry tests, the Pt/HCMSC electrode showed signifi-cantly higher electrocatalytic activity for methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) if compared with commercial Pt/Vulcan catalyst. The durability tests by cyclic voltammetry showed for the Pt/HCMSC a lower electrochemical active surface area loss than the commercial one in acidic solution. All the primary tests suggested that the Pt/HCMSC, due to its particular structure and the high dispersion of noble metal particles, is a promising catalyst for fuel cell applications, for MOR and ORR