The freshwater unicellular microalga Haematococcus pluvialis (H. pluvialis) has gained increasing attention because of its high-value metabolite astaxanthin, a super anti-oxidant. For the maximum astaxanthin production, a key problem is how to determine the senescent green vegetative phase of H. pluvialis cells to apply the astaxanthin production inducers. The conventional methods are time-consuming and laborious. In this study, a novel platform based on organic electrochemical transistor (OECT) was produced. A significant channel current change of OECTs caused by settled H. pluvialis cells on the poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) film was recorded commencing from 75 min and a stationary stage was achieved at 120 min after the combined treatment of blue light irradiation and sodium bicarbonate solution additives, which indicate the onset and maturation of the senescent green vegetative phase, respectively. Therefore, the appropriate time point (120 min after sample loading) to apply astaxanthin production inducers was determined by as-fabricated OECTs. This work may assist to develop a real-time biosensor to indicate the appropriate time to apply inducers for a maximum astaxanthin production of H. pluvialis cells.

Identifying, quantifying, and suppressing decoherence mechanisms in qubits are important steps towards the goal of engineering a quantum computer or simulator. Superconducting circuits offer flexibility in qubit design; however, their performance is adversely affected by quasiparticles (broken Cooper pairs). Developing a quasiparticle mitigation strategy compatible with scalable, high-coherence devices is therefore highly desirable. Here we experimentally demonstrate how to control quasiparticle generation by downsizing the qubit, capping it with a metallic cover, and equipping it with suitable quasiparticle traps. Using a flip-chip design, we shape the electromagnetic environment of the qubit above the superconducting gap, inhibiting quasiparticle poisoning. Our findings support the hypothesis that quasiparticle generation is dominated by the breaking of Cooper pairs at the junction, as a result of photon absorption by the antenna-like qubit structure. We achieve record low charge-parity switching rate (<1 Hz). Our aluminium devices also display improved stability with respect to discrete charging events.

In this letter, we propose and experimentally demonstrate an indium phosphide (InP) based monolithically integrated photonic microwave generator using feedback-cavities integrated dual distributed Bragg reflector laser diodes. Stable photonic microwaves are measured with a narrow 3 dB linewidth (<10 kHz). Furthermore, the kilohertz-scale narrow linewidth photonic microwaves have a widely tuning range of 1 GHz to 2.275 THz.

The photoelectrocatalytic (PEC) process has attracted much attention in the field of the decontamination of drinking water and wastewater due to its environmental friendliness and considerable efficiency. As a promising class of PEC materials, Au/TiO 2 has been focused by researchers for a long time. Nevertheless, it is still difficult to synthesize uniform Au/TiO 2 composites without the use of surface ligands, which may hinder the understanding of their intrinsic PEC properties. In this work, ligand-free Au/ highly ordered TiO 2 nanotubes (Au/hoTiO 2 NTs) with high homogeneity were prepared successfully by carefully controlling the synthesis conditions. The physical and chemical properties of Au/hoTiO 2 NTs with different Au contents were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV−vis diffuse reflectance spectroscopy, electrochemical impedance spectroscopy, life-time of photogenerated electrons, decolorization of methyl orange (MO), and photocurrent. By comparing the influence of different trapping agents, the decolorization mechanism of MO is also discussed. This work may cast light on the understanding of the inherent properties of Au/TiO 2 composites.