Tuning protein adsorption on graphene surfaces via laser-induced oxidation
An approach for controlled protein immobilization on laser-induced two-photon (2P) oxidation patterned graphene oxide (GO) surfaces is described. Selected proteins, horseradish peroxidase (HRP) and biotinylated bovine serum albumin (b-BSA) were successfully immobilized on oxidized graphene surfaces, via non-covalent interactions, by immersion of graphene-coated microchips in the protein solution. The effects of laser pulse energy, irradiation time, protein concentration and duration of incubation on the topography of immobilized proteins and consequent defects upon the lattice of graphene were systemically studied by atomic force microscopy (AFM) and Raman spectroscopy. AFM and fluorescence…
Laser-induced tuning of graphene field-effect transistors for pH sensing
Here we demonstrate, using pulsed femtosecond laser-induced two-photon oxidation (2PO), a novel method of locally tuning the sensitivity of solution gated graphene field-effect transistors (GFETs) without sacrificing the integrity of the carbon network of chemical vapor deposition (CVD) grown graphene. The achieved sensitivity with 2PO was (25 ± 2) mV pH−1 in BIS-TRIS propane HCl (BTPH) buffer solution, when the oxidation level corresponded to the Raman peak intensity ratio I(D)/I(G) of 3.58. Sensitivity of non-oxidized, residual PMMA contaminated GFETs was 20–22 mV pH−1. The sensitivity decreased initially by 2PO to (19 ± 2) mV pH−1 (I(D)/I(G) = 0.64), presumably due to PMMA residue remova…
Nanotieteen ja -teknologian hyödyntäminen ääreishermostollisessa ylemmän raajan neuroprostetiikassa
Tämä kirjallisuuskatsaus pyrkii luomaan realistisen kuvan tämän hetkisestä neuroprostetiikan alasta ja sen tulevaisuudesta, perehtymään alan ongelmiin, luomaan yhteyden nanoteknologian ja neuroprostetiikan välille ja miettimään miten ja mitä neuroprostetiikan ongelmia voitaisiin ratkaista nanoteknologialla. Suurin ongelma intuitiivisen hallinnan ja sitä kautta luonnollisen tuntuisen keinotekoisen käden saavuttamiseksi on ihmisen ja proteesin välisen yhteyden rajapinta. Nykyiset elektrodit, joilla yhteys muodostetaan ovat hermoston rakenteeseen suhteutettuna suuria ja todellisuudessa epäspesifejä. Nanoteknologian avulla käytettävien elektrodien kokoa voitaisiin pienentää,…
Tuning protein adsorption on graphene surfaces via laser-induced oxidation
An approach for controlled protein immobilization on laser-induced two-photon (2P) oxidation patterned graphene oxide (GO) surfaces is described. Selected proteins, horseradish peroxidase (HRP) and biotinylated bovine serum albumin (b-BSA) were successfully immobilized on oxidized graphene surfaces, via non-covalent interactions, by immersion of graphene-coated microchips in the protein solution. The effects of laser pulse energy, irradiation time, protein concentration and duration of incubation on the topography of immobilized proteins and consequent defects upon the lattice of graphene were systemically studied by atomic force microscopy (AFM) and Raman spectroscopy. AFM and fluorescence…