Release of Nile Red from Thermoresponsive Gold Nanocomposites by Heating a Solution and the Addition of Glutathione

Size dependency of gold nanoparticles interacting with model membranes

“…5b). The literature reports a similar intensity drop to the quenching effect of AuNPs when in the close proximity with this probe 38 and upon the addition of cholesterol to DOPC vesicles 40 , attributed to increased water penetration in the interfacial region of the membrane (where NR is located). It is expected that membrane remodelling upon introduction of small nanoparticles would result in increased contact with NR and also water penetration due to the volume remodelling.…”

“…If dispersed in aqueous solution, the fluorescence of NR is quenched by water as this probe is sensitive to polarity 37 but the probe emits fluorescence when is embedded in the tail region of the lipid membrane. In addition, NR can also be quenched, and therefore lose its inherent fluorescent properties, when in close proximity with metallic nanoparticles, through fluorescence resonance energy transfer 38 . Furthermore, the NR emission maxima changes as a function of solution polarity in a way that a blue shift in emission is attributed to a decrease in environment polarity, whilst, a red shift in emission is attributed to an increase in environment polarity 39 .…”

Colorimetric assay of homocysteine using gold nanoparticles conjugated with thermoresponsive copolymers

“…We have reported spontaneous disassembly of glutathione in a previous paper. 48 The bulkiness and negative charges of glutathione under neutral conditions facilitate the spontaneous disassembly of the AuNPs. The dissociated carboxyl groups in 3-mercaptopropionic acid and thioglycolic acid also facilitate the disassembly owing to the accumulation of negative charges when these compounds are attached to the surface of AuNPs.…”

“…We have developed a colorimetric assay for cysteine and related substances based on this inhibition. [45][46][47][48] The a* values in CIE L*a*b* colour coordinates 49 successfully quantify the colorimetric change between red and bluish purple because it responds to the change from green to red. 50,51 Because homocysteine and cysteine inhibited the disassembly of the assembled AuNPs conjugated with p(NIP-TETA) equally, the system could not distinguish homocysteine from cysteine.…”

Molecularly Bridged Gold Nanoparticle Array for Sensing Applications

“…[12][13][14][28][29][30][31][32][33][34] In principle, bottom-up fabrication is achieved through the binding, interaction, self-assembly, and self-organization characteristics of molecules and materials as building blocks. [35][36][37][38][39] Precise control of the spacing between the fabricated electrodes for specific molecules is expected to allow ultrasensitive sensing. Nanogap devices provide a sufficient level of sensitivity, as few as a single molecule to a small number of molecules, with the direct transduction of moleculespecific binding events into electrical signals.…”