Biofunctional few-layer metal dichalcogenides and related heterostructures produced by direct aqueous exfoliation using phospholipids

We report a novel, inexpensive and green method for preparing aqueous dispersions of various biofunctional transition-metal dichalcogenides (MoS2, WS2, TiS2 and MoSe2) and their related heterostructures directly via ultrasonic exfoliation mediated by the presence of phospholipids. The dispersions predominantly consist of few-layer flakes coated with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), as confirmed by Raman, photoluminescence and X-ray photoelectron spectroscopies. The phospholipid coating renders the flakes biofunctional, which coupled with the unique properties of transition-metal dichalcogenides and their heterostructures, suggests this method will have great potential in biological applications.