Second harmonic spectroscopy of ZnO, BiFeO₃ and LiNbO₃ nanocrystals

Photocontrolled Release of the Anticancer Drug Chlorambucil with Caged Harmonic Nanoparticles

“…The caged derivative Clb‐CM‐DIBO was conjugated to silica coated LNO HNPs by copper‐free click reaction to achieve 3.64 μ m mg −1 loading of the active therapeutic molecule. Despite a lower second‐order susceptibility than for BFO HNPs, the harmonic emission of LNO HNPs under NIR‐light irradiation resulted in the efficient uncaging of Clb, reaching 80 % release in 25 minutes. Due to the versatility of coumarin‐4‐yl methoxy carbonyl derivatives for the photolytic release of a panel of chemical functionalities (amines, carboxylic acids, thiols, alcohols), the photosensitive tether herein developed could be used for the uncaging of a variety of therapeutic cargos.…”

“…During the last decade, harmonic nanoparticles (HNPs) which are based on noncentrosymmetric metal oxide nanocrystals have emerged as versatile imaging probes due to their efficient nonlinear response, their large range of excitation from UV to IR, their high photostability and their narrow emission signals . Among a variety of HNPs which have been evaluated for their harmonic efficiency and biocompatibility, bismuth ferrite (BiFeO 3 , BFO) and lithium niobate (LiNbO 3 , LNO) HNPs presented high second harmonic conversion efficiency, low cytotoxicity and weak hemolytic potential . Taking advantage of these favorable properties, we recently highlighted the versatility of surface‐functionalized BFO HNPs as sensitive and selective optical probes for cancer cell imaging and stem cell tracking in tissues, exploiting the simultaneous collection of second‐ and third‐order signals .…”

Dual light-emitting Yb3+,Er3+-doped La(IO3)3 iodate nanocrystals: up-conversion and second harmonic generation

“…17,18 Recently, we reported the synthesis of α-La(IO3)3 nanocrystals and the quantitative assessment of its orientation-averaged SHG efficiency 19 that was found comparable to the other HNPs of interest (KTP, BaTiO3, LiNbO3, etc). 20,21 We also evidenced the possibility of doping α-La(IO3)3 nanocrystals with Er 3+ ions by La 3+ substitution and showed that Er 3+ -doped α-La(IO3)3 nanocrystals emit both UC-PL and SHG signals under 800-nm and 980-nm excitations. Here we report on multifunctional Yb 3+ ,Er 3+ -doped α-La(IO3)3 nanocrystals demonstrating optimized UC-PL properties and a strong SHG activity.…”

“…The value here obtained at n = 1,5 is typical of the up-conversion processes in co-doped Yb 3+ ,Er 3+ systems under such excitation intensities. 25,26 In terms of relative intensities between the SHS and UC-PL signals and after a proper calibration of the wavelength-dependent response of the experimental setup 21 , the signals at 400 nm, 525 nm and 550 nm are very similar under an excitation wavelength set at 800 nm and whatever the Er content (x = 0.005, 0.01 and 0.02). However, when the resonant excitation is shifted to 980 nm, a much more efficient UC process can be noticed comparatively to the almost constant SHS signal.…”

“…MHz, 100-120 fs) as the excitation source. 19,21 Emitted signals were collected perpendicularly to the laser beam through a spectrometer (Andor Shamrock 193) coupled to a CCD camera (Andor iDus 401). The power-law dependences were obtained by adjusting the excitation power from 250 to 800 mW thanks to a half-wave plate associated with a polarizer cube.…”