Going for the gold: Single-particle cryogenic electron microscopy (cryo-EM) has become a go-to technique for structural biologists. Although data-processing and reconstruction methods have improved, innovations in sample preparation and data collection are essential to reliably achieve high-resolution reconstructions while also reducing the amount of time required per structure. Naydenova et al. tackled the issue of electron beam–induced particle movement, a major source of information loss, by designing a gold sample support that prevents buckling of the extremely thin layer of ice in which the particles are suspended (see Perspective by Rapp and Carragher). The negligible particle displacement permits extrapolation to “zero exposure” structure factors, revealing features typically lost in cryo-EM structures. Far fewer particles per unit resolution are required, which greatly accelerates structure determination, especially at high resolution. Science , this issue p. 223 ; see also p. 171

Thin metal films with nanohole arrays have opened up new opportunities in applications ranging from plasmonics to optoelectronics. However, their dependence on substrates limits not only their performance but also other application possibilities. A key challenge to overcome this limitation is to make these nanostructured films substrate-free. Here we report large-area freestanding gold nanomembranes with nanohole arrays fabricated using a replication-releasing procedure. The structures maintain spatial uniformity and pristine quality after release across the entire membrane up to 75 cm² in area and as thin as 50 nm. The freestanding nanomembranes show significantly enhanced optical transmission and effective field extension compared to the same nanomembranes on substrates. A plasmonic coupling resonance with a 2.7 nm linewidth achieves a record figure-of-merit of 240 for refractive index sensing. The gold nanomembranes can be geometrically converted to 3D microstructures by an ion-irradiation-based kirigami technique. The transformed micro-objects can be precisely controlled via geometry design and strategic cutting. Furthermore, we find the presence of nanoholes can significantly change the in-plane modulus of the gold nanomembranes. Finally, the freestanding gold nanomembranes can be transferred to non-planar substrates, enabling their future integration with advanced optical and electronic systems for emerging applications.

Enzyme-based biosensors commonly utilize the drop-casting method for their surface modification. However, the drawbacks of this technique, such as low reproducibility, coffee ring effects, and challenges in mass production, hinder its application. To overcome these limitations, we propose a novel surface functionalization strategy of enzyme crosslinking via inkjet printing for reagentless enzyme-based biosensors. This method includes printing three functional layers onto a screen-printed electrode: the enzyme layer, crosslinking layer, and protective layer. Nanomaterials and substrates are preloaded together during our inkjet printing. Inkjet-printed electrodes feature a uniform enzyme deposition, ensuring high reproducibility and superior electrochemical performance compared to traditional drop-casted ones. The resultant biosensors display high sensitivity, as well as a broad linear response in the physiological range of the serum phosphate. This enzyme crosslinking method has the potential to extend into various enzyme-based biosensors through altering functional layer components.