Large- to ultra-large-scale synthesis of nucleic acids is becoming an increasingly important tool for understanding and manipulating biological systems, as well as for developing new technologies based on engineered biological materials, including DNA-based nanofabrication, aptamers and writing digital data at the molecular level. Several technologies for large-scale synthesis have been developed over the years, but all of them remain inaccessible to most researchers due to their complexity and/or use of proprietary technologies. Here, we present a fully open source, benchtop device for ultra-large scale nucleic acid synthesis that is also highly flexible and adaptable, able to accommodate a wide range of monomers and chemistries, while providing unrestricted access to synthesis parameter space.

Although several biomedical assays have been developed to screen for antibodies against SARS-CoV-2, very few can be completed without drawing blood. We developed a rapid lateral flow screening tool that used saliva samples and yielded rapid results that could be quantified using a cell phone. This assay provided the sensitive detection of IgG antibodies against SARS-CoV-2 within 10 min. We started by synthesising, modifying, and characterising gold nanoparticles. Using these particles as a coloured label, we developed a lateral flow strip made of nitrocellulose, glass fibre, and cellulose material. We quantified our visual results using pictures acquired with a cell phone and calculated a limit of detection of 4 ng/mL of antibodies against the SARS-CoV-2 spike protein.