Silane control of the electron injection and oxygen sensitivity of dye-silane-GaN hybrid materials for luminescent chemical sensing

Ielasi, Guido; Hui, Pramiti; Palácio, Carlos; Muñoz, E.; Orellana, Guillermo

doi:10.1016/j.snb.2017.07.203

Cited by 5 publications

(1 citation statement)

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“…In contrast, no degradation of the self-assembled monolayers occurred on p-GaN surfaces upon UV irradiation [ 31 ]. Moreover, dye functionalized p-GaN surfaces appeared to be highly sensitive to oxygen exposure, in contrast to n-GaN surfaces, where no changes in the emission lifetime of a ruthenium dye were observed, due to the high deactivation efficiency of the dye [ 32 , 33 ]. Until now, mainly specific case studies on GaN functionalization have been reported, and a systematic investigation and understanding of the surface chemistry of differently functionalized sensor surfaces is still elusive, which limits the potential for designing improved GaN-based biosensors.…”

Section: Introductionmentioning

confidence: 99%

Impact of Surface Chemistry and Doping Concentrations on Biofunctionalization of GaN/Ga‒In‒N Quantum Wells

Naskar

Schneidereit

Huber

et al. 2020

Sensors

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The development of sensitive biosensors, such as gallium nitride (GaN)-based quantum wells, transistors, etc., often makes it necessary to functionalize GaN surfaces with small molecules or even biomolecules, such as proteins. As a first step in surface functionalization, we have investigated silane adsorption, as well as the formation of very thin silane layers. In the next step, the immobilization of the tetrameric protein streptavidin (as well as the attachment of chemically modified iron transport protein ferritin (ferritin-biotin-rhodamine complex)) was realized on these films. The degree of functionalization of the GaN surfaces was determined by fluorescence measurements with fluorescent-labeled proteins; silane film thickness and surface roughness were estimated, and also other surface sensitive techniques were applied. The formation of a monolayer consisting of adsorbed organosilanes was accomplished on Mg-doped GaN surfaces, and also functionalization with proteins was achieved. We found that very high Mg doping reduced the amount of surface functionalized proteins. Most likely, this finding was a consequence of the lower concentration of ionizable Mg atoms in highly Mg-doped layers as a consequence of self-compensation effects. In summary, we could demonstrate the necessity of Mg doping for achieving reasonable bio-functionalization of GaN surfaces.

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Section: Introductionmentioning

confidence: 99%