Gold nanorods as a high-pressure sensor of phase transitions and refractive-index gauge. Issue 18 (24th April 2019)

• Record Type: Journal Article
• Authors: Runowski, Marcin; Sobczak, Szymon; Marciniak, Jędrzej; Bukalska, Ida; Lis, Stefan; Katrusiak, Andrzej
• Is Part Of: Nanoscale. Volume 11:Issue 18(2019)
• Page Start: 8718
• Page End: 8726
• Publication Date: 2019-04-24
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c9nr02792k
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : SPR vis-NIR spectroscopy of Au nanorods conveniently detects phase transitions and measures the refractive index under high pressure. Abstract : Gold nanorods (Au NRs), nanospheres and other nanoparticles display numerous superior physicochemical properties, such as resistance to oxidation and aggressive agents, strong enhancement of local electric field and a high absorption coefficient in the visible and near-infrared (NIR) range. The absorption peaks of surface plasmon resonance (SPR) in Au NRs are highly sensitive to their surrounding medium and to its refractive index (RI) changes. However, no applications of NRs for detecting phase transitions have been reported. Here, we show that Au NRs effectively detect phase transitions of compressed compounds, liquid and solid, by measuring their RI. Owing to the direct interaction of the NRs with their surrounding medium, its subtle RI changes can be observed by the use of high-pressure absorption vis-NIR spectroscopy. We have applied a Au NR-based sensor in a diamond anvil cell (DAC) for monitoring the phase transitions of compressed water, its freezing to ice VI and at the subsequent solid–solid phase transition to ice VII, and the monotonic compression and solid–solid phase transitions in urea and thiourea.