Use of an Ethanol-Driven Pressure Cell to Measure Hydrostatic Pressure Response of Protein-Stabilized Gold Nanoclusters

Abstract : In this investigation, an improved method to study the fluorescence enhancement of bovine serum albumin (BSA)-stabilized gold nanoclusters (BSA:Au25NCs) at low pressures is introduced. This method uses an ethanol-driven pressure cell (PC) incorporated into a spectrofluorometer to measure the pressure sensitivity of BSA:Au25NCs. The ethanol-driven PC allows for the application of hydrostatic pressure at a much lower range and with higher repeatability than current methods of pressure testing, which involve using a Diamond Anvil Cell (DAC). Results demonstrate that the pressure response of BSA:Au25NCs studied in the fluorometer-based PC exhibited a linear fluorescence response upon pressure loading. These data correlated well with the previously published results obtained using the DAC technique at pressures above 200 MPa. Overall, the PC used in this study was better suited to detect pressure sensitivity at pressures under 200 MPa, while exhibiting much improved repeatability over current DAC techniques, making it ideal for testing the pressure sensitivity of metal nanoclusters.