This paper describes an easy-to-handle approach to create three-dimensional millimeter-scale (or submillimeter-scale) polymeric structures on various substrates that have been used as molds in order to develop a polymeric-based manufacturing procedure for making in vitro diagnostic devices with mass production capacity and portability. These polymeric structures were made by using UV-activated materials, adhesive tapes as the mask, and a UV-LED flashlight as the portable light source. This straightforward approach can be easily performed and has great potential for use in resource-limited settings. The ability to conduct three common metabolic assays – for glucose, total cholesterol, and nitrite ions in this study – in both a buffer system and human serum (analytical validation, US FDA regulations) with clinically relevant sensitivity has been demonstrated using these polymeric-based in vitro diagnostic devices. This study, we believe, would provide for a wide range of potential applications such as the development of in vitro diagnostic devices, and a large-scale, low-cost, and easy-to-handle fabrication procedure for either developing regions or resource-limited settings, and, ultimately, for the development of “zero-cost” diagnostic devices for global public health.