“…Additionally, the refractive index sensitivity of gold nanorods is linearly proportional to the aspect ratio, facilitating its tunability [97]. Nanostructures of other shapes, including nanocubes [106][107][108][109], nanoshells [110][111][112], nanodiscs [113][114][115], nanotriangles [116,117], nanostars [118][119][120], nanobipyramids [121,122], nanorice [123,124], nanoholes [125,126], and nanocrescents [56,[127][128][129][130], have also been investigated and expanded to nanocubes and nanocuboids enclosed with concave surfaces (Fig. 1).…”