Selective growth of α-form zinc phthalocyanine nanowire crystals via the flow rate control of physical vapor transport   Youngkwan Yoon, Soyoung Kim and Hee Cheul Choi*     A technique for growing nanomaterials useful for treating cancer has been developed by researchers in South Korea. Nanowires have nanoscale diameters but much greater lengths and are useful in a wide range of applications. Zinc phthalocyanine nanowires, for example, can be injected into a tumor and heated using light to destroy the cancerous cells. These wires come in two forms: the α-form is more effective for this photodynamic therapy due to increased water dispersibility, but many methods for synthesising zinc phthalocyanine nanowires tend to produce the less favourable β-form. Hee Cheul Choi and colleagues from the Pohang University of Science and Technology have developed a method for creating α-form zinc phthalocyanine nanowires. The key to their success is to carefully control the flow rate of a gas carrying zinc phthalocyanine molecules across a silicon substrate.   https://www.nature.com/articles/s41427-020-0198-7