Diffusion-driven height readout analytical device based on gold nanobipyramid-doped supramolecular hydrogel for point-of-care bioanalysis.

Point-of-care (POC) diagnostics is crucial for rapid on-site detection in resource-limited settings. However, there are still some challenges in the development of quantitative POC bioassays. Herein, we propose a simple, visual, and instrument-free height readout analytical device injected with target-responsive gold nanobipyramid (AuNBP)-doped guanosine-quartet (G4) supramolecular hydrogel for the quantitative detection of glucose. This sensing platform relies on H 2 O 2 generated by glucose oxidation to induce iodide-mediated etching of AuNBPs, resulting in visualized color-changed hydrogel bar-chart driven by molecular diffusion in a polycarbonate tube. The visual height of the color-changed hydrogel is correlated with the concentration of glucose, and the quantitative determination was achieved simply by using a household ruler or mobile software as a readout. More importantly, this method has been successfully used to detect glucose in human serum samples with high accuracy and reliability. In addition, the AuNBPs are utilized as plasmonic probes to construct two-input logic gates, providing an intelligent strategy to simultaneously detect multiple biomolecules. This height-readout sensing platform demonstrates great promise for applications in POC and intelligent bioanalysis. [Display omitted] • A G4 hydrogel-based height readout analytical device was developed for quantitative glucose POC detection. • This POC bioassay was based on surface etching of AuNBPs and diffusion-driven strategies. • This method has been successfully used to detect glucose in human serum samples with high accuracy and reliability. • Only a low-cost PC tube loaded with AuNBP-doped supramolecular hydrogel is required for glucose detection. [ABSTRACT FROM AUTHOR]