Control of pore structure in a porous gold nanoparticle for effective cancer cell damage

For tumor treatment, compared with gold nanoparticles (NPs) of other geometries, a porous gold NP (PGNP) has the advantages of stronger localized surface plasmon resonance (LSPR) due to the pore nanostructures and a larger surface area to link with more drug or photosensitizer (PS) molecules for more effective delivery into cancer cells. Different from the chemical synthesis methods, in this paper we demonstrate the fabrication procedures of PGNP based on shaped Au/Ag deposition on a Si substrate and elucidate the advantageous features. PGNPs fabricated under different conditions, including different deposited Au/Ag content ratios and different alloying annealing temperatures, are compared for optimizing the fabrication condition in terms of LSPR wavelength, PS linkage capability, and cancer cell damage efficiency. It is found that within the feasible fabrication parameter ranges, the Au/Ag content ratio of 3:7 and alloying annealing temperature at 600 °C are the optimized conditions. In comparing with widely used gold NPs of other geometries, PGNP fabricated under the optimized conditions can be used for achieving a significantly higher linked PS molecule number per unit gold weight.