Along with the advance in medical research, more biomarkers emerge as useful indicators for both disease and health index. However, majority of them have no practical or economic testing methods available yet, or rely on high-costing methods such as Enzyme-Linked Immuno-Sorbent Assay (ELISA), High-Performance Liquid Chromatography (HPLC), Mass Spectrum, and immunohistochemistry (IHC). In this article, we develop a universal nanozyme integrated testing platform for biological molecules that incorporates the electrochemical measurement of glucose with lateral flow immunostrip (LFS) for target analytes. This design involves the quantitative conversion of analytes into invertase and then glucose, which can be measured by an extremely affordable meter. The feasibility of this design was validated using 8-hydroxy-2'-deoxyguanosine (8-OHdG) and prostate specific antigen (PSA) as representatives for small molecules and moderate to large proteins respectively. Our approach yields results comparable to commercial diagnostic ELISA kits at a substantially reduced cost and reaction time. Specifically, the design has a detection limit of 0.23 ng mL-1 for 8-OHdG and 1.26 ng mL-1 for PSA, and a detection range of 0.1-100 ng mL-1 for 8-OHdG and 1-100 ng mL-1 for PSA. By combining the accessibility of well-established glucose testing and LFS, our design can serve as a point of care testing method that can be fully integrated into the personal lifestyle without requiring professional assistance.
Keywords: Cancer biomarker; Glucose meter; Lateral flow strip; Nanozymes; Point-of-care testing; Universal platform.
Copyright © 2018 Elsevier B.V. All rights reserved.