Open waste burning, large-scale fires, and maritime disasters produce partially burnt plastic called "pyroplastic". Chemical markers would provide a complementary method to appearance and physical properties for identifying pyroplastics in environmental samples, particularly with respect to microplastics. Pyroplastic can contain significant quantities and unique distributions of parent polycyclic aromatic hydrocarbons (PAHs) with molecular weights up to 278 Da. Because of this enrichment, we considered whether large PAHs (≥24 ringed-carbons) could serve as chemical markers for pyroplastics. To address this, we developed a high-temperature method for gas chromatography atmospheric pressure chemical ionization (GC-APCI) coupled with tandem mass spectrometry (MS/MS) to target large PAHs with molecular weights ranging from 314-424 Da. Method development was performed using National Institute of Standards and Technology standard reference materials (SRMs) previously characterized for PAHs greater than 302 Da. A PAH class-specific MS/MS acquisition scheme combined with a simple, generic microextraction provided sensitive and specific detection without the need for sample fractionation or cleanup. Pyroplastics collected during the 2021 M/V X-Press Pearl ship fire and plastic spill were analyzed. A semiquantitative comparison showed that the pyroplastic samples contained over 2 orders of magnitude more of the 16 large PAHs (314-424 Da) than unburnt plastic pellets, reflecting previously observed trends for parent PAHs up to 278 Da. Qualitative comparison of samples and SRMs revealed multiple potential candidates (including 1,3,5-triphenylbenzene) suitable for further study as markers of pyroplastics in complex environmental samples. A suite of chemical markers for pyroplastics should prove helpful in monitoring efforts for air quality, waste management, microplastic pollution, and fires at the forest-urban interface.
Flat photonic bands promise extreme control of light-matter interactions but are often degraded by loss and angular dispersion. We demonstrate robust polaritonic flatbands in WS2 dimer metasurfaces by strongly coupling an engineered quasibound state in the continuum (q-BIC) to intrinsic WS2 excitons. The photonic mode, realized via suppression of the first-order Fourier harmonic and originating from an anapolelike interference between electric dipole and magnetic quadrupole moments, forms an ultraflat band with an angle-conserved quality factor. Upon strong coupling, distinct upper and lower polariton branches emerge with a vacuum Rabi splitting of 190 meV. Crucially, both branches inherit the dispersionless character of the parent q-BIC, maintaining nearly constant resonance energy, linewidth, and amplitude over a wide angular range, even when anapole conditions are broken by material loss. This identifies a mechanism transition from interference-based to inheritance-based dispersion control, in which lattice-determined photonic dispersion and energy-selective coupling ensure resilience against loss. The resulting angle-invariant polaritonic response, compatible with substrate-supported implementations and external-cavity-free architectures, opens avenues for wide-angle sensing and ultralow-threshold polariton lasing, establishing a versatile platform for flatband engineering in the strong-coupling regime.
Optically-active spin qubits have emerged as powerful quantum sensors capable of nanoscale magnetometry, yet conventional coherent sensing approaches are ultimately limited by the coherence time of the sensor, typically precluding detection in the sub-MHz regime. We present a broadly applicable fluorescence-encoding method that circumvents coherence-time constraints by transducing time-varying magnetic fields directly into modulated fluorescence signals. Using nitrogen-vacancy centers in diamond as a model system, we demonstrate shot-noise-limited sensitivity for AC magnetic fields spanning near-DC to MHz frequencies, with detection bandwidth tunable via optical excitation power. The technique captures complete spectral information in a single measurement, eliminating the need for point-by-point frequency scanning, and allows phase-sensitive multi-frequency detection with Hz-level resolution. This approach transforms quantum sensors into atomic-scale spectrum analyzers, with immediate applications for low-frequency RF communication, zero-field NMR, and bioelectronic sensing. Our approach is broadly applicable to the expanding class of optically-active spin qubits, including molecular systems and fluorescent proteins, opening new sensing regimes previously inaccessible to coherent techniques
Gold nanoparticles have been studied extensively for various medical applications due to their strong capability for cancer treatment without drugs and their equally strong, but newly identified, potential in the anti-bacterial field. Due to their ease of synthesis, chemical stability, activation by light, and controllable toxicity, gold nanomaterials have attracted enormous interest as novel biomaterials, especially for cancer patients who have an increased rate of infection due to a compromised immune system. This review discussed how gold nanoparticle used in the anti-bacterial and anti-cancer fields, as well as their prospect in further medical research to combine such multi-properties into one kind nanoparticle. Given the adverse impacts of the pandemic spanning 2020 to 2022, a considerable number of research projects were either interrupted or prematurely terminated. As a direct consequence, this review solely encompasses the research progress attained prior to the onset of the pandemic. Notably, the core unresolved issues within this research domain—with specific focus on topics centered around gold nanoparticles—continue to be the subject of ongoing investigation to the present day.
