Two brilliant outcomes of supramolecular self-assembly directed, low molecular weight organic gelator based self-healable Co(II) and Ni(II) metallogels were achieved. The adipic acid as the low molecular weight organic gelator...

Two protein-based self-healing Cu(II)-metallohydrogels named BSA-CuA and BSA-CuCl have been synthesized by mixing acetate and chloride salts of Cu(II) distinctly with the protein bovine serum albumin (BSA) in water medium. Experimentally investigated rheological parameters of both synthesized metallohydrogels not only expose the viscoelastic semi solid nature and mechanical toughness but also reveal the self-healing properties of both metallohydrogel materials. Counteranion-directed morphological variations of these metallohydrogels are visualized through field-emission scanning electron microscopic images. The third-order optical nonlinear susceptibility x (3) of these synthesized metallohydrogels has been studied using the Z-scan technique at a wavelength of 550 nm under the femtosecond regime in the excitation intensity range from 66 to 283 GW/cm 2 . BSA-CuA and BSA-CuCl metallohydrogels exhibit a high value of the positive nonlinear refractive index n 2 I and two-photon absorption coefficient β eff , which are very important for all-optical switching, optical limiting, and other photonic applications. The polarity possibly associated with the self-healing property of these two synthesized metallohydrogels has been justified through the experimentally measured high value of optical nonlinearity. At 88 GW/cm 2 intensity of the excitation beam, the n 2 I values for BSA-CuA and BSA-CuCl are (14.40 ± 0.16) × 10 −7 cm 2 /GW and (10.99 ± 0.15) × 10 −7 cm 2 /GW, respectively, and at 283 GW/cm 2 intensity, the β eff values are (0.0662 ± 0.0002) cm/GW and (0.0540 ± 0.0001) cm/GW, respectively. The (x (3) ) of BSA@CuA and BSA@CuCl at 283 GW/cm 2 is (1.757 ± 0.018) (esu ×10 −14 ) and (1.560 ± 0.017) (esu ×10 −14 ), respectively.

A single chromophore based dinitrophenylsulphonyl–naphthalene–chlorambucil conjugate drug delivery system is presented for the dual stimuli controlled release of SO2 and chlorambucil.

The synergistic effect of zinc selenide (ZnSe) nanoparticle functionalized into reduced graphene oxide (RGO) sheets on nonlinear optical (NLO) properties has been investigated by single beam z-scan technique. Comprehensive measurements on nonlinear absorption (NLA) as well as nonlinear refraction (NLR) have been performed on RGO, ZnSe, and RGO-ZnSe composites at 630 nm in the femtosecond regime. Both NLA and NLR of RGO-ZnSe show an enhancement in NLO properties compared to pure RGO and ZnSe in an intensity range of 37GW/cm2 to 130GW/cm2. The enhanced optical nonlinearity of RGO-ZnSe may have been caused due to strong interlayer coupling between RGO and ZnSe, as well as the availability of a large number of NLA states in the composite. The interlayer coupling between ZnSe nanoparticles and RGO sheets has been confirmed by transmission electron microscopy, UV-Visible, and photoluminescence spectroscopy. At low input pulse intensity (∼37GW/cm2), saturation absorption dominates, whereas NLA becomes prominent in the higher intensity regime (55GW/cm2–130GW/cm2) for RGO and ZnSe. NLA is the dominant phenomenon for RGO-ZnSe in the whole experimental intensity range. Moreover, it is observed that the dispersion of RGO, ZnSe, and RGO-ZnSe in dimethylformamide exhibits positive NLR. This study indicates an enhancement in nonlinear optical response of the RGO-semiconductor composite, which is very promising for graphene based photonic device applications.

The β-carboline moiety, substituted at the C1 and C3 benzylic positions with a leaving group, has been demonstrated for the first time as a photoremovable protecting group for time-dependent sequential release of two (same or different) carboxylic acids upon one- and two-photon light irradiation. Density functional theory calculations suggest that the electronic environment of the β-carboline moiety at C1 and C3 positions plays a key role in the rate of photorelease.