In vitro somatic embryogenesis and regeneration of somatic embryos to whole plants through micropropagules was successfully demonstrated from pigmented uniseriate filamentous callus of Kappaphycus alvarezii (Doty) Doty in axenic cultures. More than 80% of the explants cultured on 1.5% (w/v) agar‐solidified Provasoli enriched seawater (PES) medium showed callus development. The callus induction rate was consistently higher for laboratory‐adapted plants. The excised callus grew well in subcultures and maintained its growth for prolonged periods if transferred to fresh medium in regular intervals. Some subcultured calli (<10%) did undergo transformation and produced densely pigmented spherical or oval‐shaped micropropagules (1–5 mm in diameter) that subsequently developed into young plantlets in liquid PES medium. The micropropagule production was further improved through somatic embryogenesis by a novel method of culturing thin slices of pigmented callus with naphthaleneacetic acid (NAA) or a mixture of NAA and 6‐benzylaminopurine. Transfer of embryogenic callus along with tiny somatic embryos to liquid medium and swirling on orbital shaker facilitated rapid growth and morphogenesis of somatic embryos into micropropagules that grew into whole plants in subsequent cultivation in the sea. The daily growth rate of one tissue cultured plant was monitored for seven generations in field and found to be as high as 1.5–1.8 times over farmed plants. The prolific somatic embryogenesis together with high germination potential of somatic embryos observed in this study offers a promising tool for rapid and mass clonal production of seed stock of Kappaphycus for commercial farming.

A simplistic design of a self-powered UV-photodetector device based on hybrid r-GO/GaN is demonstrated.Under zero bias, the fabricated hybrid photodetector shows a photosensivity of ∼ 85% while ohmic contact GaN photodetector with identical device structure exhibits only ∼5.3% photosensivity at 350 nm illumination (18 µW/cm 2 ). The responsivity and detectivity of the hybrid device were found to be 1.54 mA/W and 1.45×10 10 Jones (cm Hz ½ W −1 ), respectively at zero bias with fast response (60 ms), recovery time (267 ms) and excellent repeatability. Power density-dependent responsivity & detectivity revealed ultrasensitive behaviour under low light conditions. The source of observed self-powered effect in hybrid photodetector is attributed to the depletion region formed at the r-GO and GaN quasi-ohmic interface.The tremendous progress in gallium nitride (GaN) based light emitting diodes (LEDs), 1 laser diodes 2 , and other GaN based devices, namely, UV photodetector (PD) has attracted a great deal of interest from research community. 3 Being chemically inert and thermally stable, they are the most suitable for applications such as flame detection, secure space communication and ozone layer monitoring. 4,5 To match the requirements for such applications in remote and extreme environment, it is highly desirable for the UV devices to be ultrasensitive, with fast response and operate in self-powered mode. However, inherent high defect density associated with as-grown epitaxial GaN films limits its performance. 6The various schemes of metal-semiconductor (M-S) interfaces have been used to improve the UV-PDs device performance. The use of two different metal electrodes on n-GaN with modulating Schottky barrier height leads to a fast response speed but limited reverse saturation current density. 7 Earlier study has shown Schottky contact photodiode of Ni/GaN/Au with asymmetric interdigitated finger electrodes having a responsivity of 5 mA/W in self-powered mode at UV illumination. 8 Recently, Sun et al. have reported a high responsivity of 104 mA/W at zero bias voltage of interdigitated Schottky contact photodiode of Ni (80 nm) /GaN/Ti (20 nm) /Al (60 nm) device. 9 On the other hand, the use of highly transparent conductive electrodes (TCE) such as indium-tin-19 W. S. Hummers and R. E. Offeman, J. Am. Chem. Soc. 80, 1339 (1958).

Direct measurements of the valence ionization energies and the reorganization energies of the three aromatic amino acids, l-tyrosine, l-tryptophan, and l-phenylalanine, in aqueous solution using the liquid microjet technique and two different photoemission methods-X-ray photoelectron spectroscopy (XPS) at 175 eV photon energy and resonant two-photon ionization (R2PI) using 2 × 267 nm (2 × 4.64 eV) UV laser light-are reported. l-Tryptophan has the lowest vertical ionization energy, 7.3 eV, followed by tyrosine (7.8 eV) and phenylalanine (∼8.7 eV). Essentially, no variation in recovered orbital energies is observed comparing near threshold ionization to X-ray ionization. Superior sensitivity of the (background-free) R2PI scheme for solutions with very low solute concentration (<2 mM) is demonstrated in contrast to the single-photon XPS measurements, which often requires solute concentrations of 0.1-1 molar. This higher sensitivity along with chemical selectivity of the R2PI technique can be exploited for both spectroscopic assignment and as an analytical tool. The nature of the adiabatic ionization energy for the three aromatic amino acids has been explored by the R2PI approach and by empirically formulating the correlation between the estimated ionization onset with electronic and nuclear relaxation on the excited state surface. Our results have implications for understanding one-electron transfer within enzymes and in redox situations where (ir)reversible deprotonation occurs such as those manifest in the biochemistry of oxidation damage.

Compact optical detectors with fast binary photoswitching over a broad range of wavelength are essential as an interconnect for any light‐based parallel, real‐time computing. Despite of the tremendous technological advancements yet there is no such single device available that meets the specifications. Here a multifunctional self‐powered high‐speed ultrabroadband (250–1650 nm) photodetector is reported based on graphitic carbon‐nitride (g‐C3N4)/Si hybrid 2D/3D structure. The device shows a novel binary photoswitching (change in current from positive to negative) in response to OFF/ON light illumination at small forward bias (≤0.1 V) covering 250–1350 nm. At zero bias, the device displays an extremely high ON/OFF ratio of ≈1.2 × 105 under 680 nm (49 µW cm−2) illumination. The device also shows an ultrasensitive behavior over the entire operating range at low light illuminations, with highest responsivity (1.2 A W−1), detectivity (2.8 × 1014 Jones), and external quantum efficiency (213%) at 680 nm. The response and recovery speeds are typically 0.23 and 0.60 ms, respectively, under 288 Hz light switching frequency. Dramatically improved performance of the device is attributed to the heterojunctions formed by the ultrathin g‐C3N4 nanosheets embedded in the Si surface.