Phospholipid-stabilized CuxAg1-xInSe2 Nanocrystals as luminophores: Fabrication, Optical Properties and Biological Application
Ternary I-III-VI semiconductors-based nanocrystals (NCs) exhibit a wide range of applications in optoelectronics, photovoltaics and biolabeling. This motivates the in-depth study of method to synthesize and exploration of optical property of them. We present an approach for the synthesis of quaternary CuxAg1-xInSe2 (x = 0~1) NCs by means of the cation exchange reaction starting from AgInSe2 NCs. By tailoring the thermodynamic and kinetic parameters, control over both the composition and bandgap was successfully achieved. The optical properties demonstrated significant nonlinear behavior that the photoluminescence (PL) wavelength and bandgap evolve steeply at a range of x < 0.5 but become invariant when x > 0.5. Optical characterizations indicated that two distinct transition processes, i.e. donor-acceptor-pair and free-to-bound recombinations, dominate the PL emissions for CuxAg1-xInSe2 NCs with different x range. Furthermore, the obtained NCs were directly modified with phospholipid. In vitro experiments illustrated that phospholipid-decorated CuxAg1-xInSe2 NCs have excellent biocompatibility and could be used as the fluorescence marker for fast bioimaging of cancer cells and cancer stem cells in visible and NIR region.