On-chip gas sensors are crucial for environmental and health monitoring but have struggled with high sensitivity. A team from PolyU has now developed a novel suspended chalcogenide waveguide photothermal spectroscopy that dramatically enhances the on-chip sensing performance. The chip-scale sensor achieves an unprecedented detection limit of 330 ppb for acetylene gas, a large dynamic range for 6 orders of magnitude, and fast response under 1 second, setting a new benchmark for integrated photonic gas sensors.

A groundbreaking development in VCSEL technology enables a 1 MHz linewidth for chip-scale atomic clocks. By integrating a passive cavity into the device, this VCSEL achieves ultra-stable, single-mode operation with enhanced frequency stability, even at elevated temperatures. The technology offers promising solutions for next-generation quantum sensors, positioning VCSELs as compact and scalable options for precision timing, quantum sensing, and high-performance frequency references.

Aqueous zinc batteries (ZBs) represent a promising sustainable and safe energy storage technology, yet their widespread adoption is impeded by persistent interfacial instabilities at Zn anodes. This study reports a polyhydroxy hydrogel electrolyte (PASHE) with in situ regulated interface chemistry suitable for biosensing compatible ZBs. Benefiting from the well-integrated interface via in situ strategy, the hydroxyl-rich L-sorbose in PASHE establishes kinetically favorable Zn²⁺ transport pathways and regulates interfacial ion-adsorption hierarchies, synergistically homogenizing ion distribution and promoting preferential crystallographic orientation. Furthermore, PASHE constructs a low water-activity microenvironment via interfacial preferential adsorption, oxygen-rich solid electrolyte interphase evolution, and Zn²⁺ solvation sheath reconstruction. These effects enable Zn (002)-textured electrodeposition and inhibitory side reactions, achieving dendrite-free Zn plating/stripping with exceptional stability (3300 h in Zn//Zn cells) and near-perfect reversibility (average coulombic efficiency of 99.6% over 1200 cycles in Zn//Cu cells). This strategy delivers unprecedented cyclability in flexible Zn//I₂ batteries (94.9% retention after 9000 cycles) and Zn-ion hybrid capacitors (98.0% after 43,000 cycles). Notably, we demonstrate an integrated biosensing platform that couples PASHE-based biosensor with cascaded Zn//I₂ batteries, realizing real-time monitoring of physiological signals and biomechanical motions. This work proposes dual strategies of in situ approach and functional additive to design hydrogel electrolytes, bridging high-performance ZBs with next-generation biosensing technologies.

Kyoto, Japan -- The stability of the iron atom's nucleus has made it one of the most abundant heavy elements in the universe. When excited, iron atoms emit distinctive fluorescent X-ray lines which can be identified using the Fe Kα emission line, an approximately 6.4 keV fluorescent line produced when an electron transitions from the 2p orbital to the 1s orbital of the atom.

The Fe Kα emission line is widely used as a diagnostic tool for understanding the physical conditions of matter across a variety of astronomical objects. The energy of an emission line depends on the ionization state of iron: the degree to which its electrons have been stripped away. As ionization progresses and electrons are removed, the effective electric attraction between each remaining electron and the atomic nucleus becomes stronger.

From this, one might expect the energy of the Fe Kα emission line to increase as ionization increases. However, theoretical studies have demonstrated that, for iron, there exists a limited range of low ionized states in which the energy of the Fe Kα line sees a slight decrease instead of an increase. This happens because during the removal of electrons from the 3d orbital, the repulsion between electrons within the 3d shell is reduced, and the 3d orbital contracts toward the nucleus. While the Fe Kα emission line corresponds to the 2p → 1s transition, the Fe Kβ line corresponds to the 3p → 1s transition, and this line increases almost uniformly with increasing ionization.

Heavy metal pollution is quietly threatening global food security by poisoning agricultural lands. While environmental scientists have long used charred organic materials to trap toxins like cadmium in the soil, the traditional high-heat baking process is expensive and energy-intensive. Now, an international research team has developed a highly efficient, budget-friendly alternative called "oxychar" that pulls double duty—soaking up both agricultural ammonia and toxic cadmium at the same time.

Cadmium contamination in agricultural soils threatens food safety worldwide, as the toxic metal can accumulate in crops and enter the human food chain. A new study published in the journal Biochar reports that aging silicon-rich biochar derived from rice husks can significantly reduce cadmium uptake in leafy vegetables while improving plant resistance to heavy metal stress.

A new study reports that a biochar-enhanced photocatalyst can efficiently degrade antibiotic contaminants in water, offering a promising strategy for addressing one of the growing threats to global water quality.

Electrochemical capacitors, often called supercapacitors, are the sprinters of the energy world. They charge instantly and deliver massive bursts of power on demand. The trade-off, however, is their lack of endurance: they cannot store much total energy, and they tend to leak their charge quickly when sitting idle. While engineers know that cranking up the operating voltage could solve the energy density problem, doing so almost always causes the internal chemical bath (the electrolyte) to break down and fail.

Researchers at Rice University recently convened an international group of scientists to explore how artificial intelligence and machine learning could transform one of the world’s most ambitious physics experiments: the Deep Underground Neutrino Experiment (DUNE). Held March 10-12 at Rice’s BioScience Research Collaborative, the three-day workshop brought together researchers from universities, national laboratories and international partners to discuss how the experiment’s software and computing infrastructure can better support the growing role of AI and machine learning. The event was organized by DUNE’s AI/ML Forum and Core Software and Computing Consortium and was partially supported by the Rice Creative Ventures Fund.