Recently, directed approaches which are driven by light or external electric, magnetic, and acoustic fields have emerged as versatile solutions to achieve the assembly of NPs at specific regions on surfaces . Optically-directed assembly of gold nanoparticles (AuNPs) offers the capability to fabricate plasmonic substrates ondemand with tailorable structure. AuNPs are capable of heating under irradiation through plasmon-enhanced photon-phonon conversion, which can be used to form a temperature gradient in liquids. The manipulation of a wide number of species is possible due to their different response to this gradient, directing them towards or outwards the target area. The Soret effect, also termed thermophoresis, describes the motion of particles within a liquid mixture when subjected to a thermal gradient. Under a thermal gradient, a solute of concentration c contained in a liquid has a flux density defined as