Printed Ultrastable Bioplasmonic Microarrays for Point-of-Need Biosensing

Abstract

Paper-based point-of-need (PON) biosensors are attractive for various applications, including food safety, agriculture, disease diagnosis, and drug screening, owing to their low cost and ease of use. However, existing paper-based biosensors mainly rely on biolabels, colorimetric reagents, and biorecognition elements and exhibit limited stability under harsh environments. Here, we report a label-free paper-based biosensor composed of bioplasmonic microarrays for sensitive detection and quantification of protein targets in small volumes of biofluids. Bioplasmonic microarrays were printed using an ultrastable bioplasmonic ink, rendering the PON sensors excellent thermal, chemical, and biological stability for their reliable performance in resourcelimited settings. We fabricated silicone hydrophobic barriers and bioplasmonic microarrays with direct writing and droplet jetting approaches on a three-dimensional (3D) nanoporous paper. Direct writing hydrophobic barriers can define hydrophilic channels less than 100 μm wide. High-resolution patterning of hydrophilic test domains enables the handling and analysis of small fluid volumes. We show that the plasmonic sensors based on a vertical flow assay provide similar sensitivity and low limit of detection with a 60 μL sample volume compared to those with 500 μL samples based on an immersion approach and can shorten assay time from 90 to 20 min.

Plasmonic Nanostructures-Decorated ZIF-8-Derived Nanoporous Carbon for Surface-Enhanced Raman Scattering

“…47 Paper has been demonstrated to be an attractive substrate for flexible biochips owing to their unique properties, such as flexibility, high specific surface area, and abundance. 1,53 Hence, paper has been employed as the flexible substrate in this study. We first decorated plasmonic nanostructures on NPC, which shows the uniform adsorption of porous Au@Ag NRs on NPC (Figures S10 and S11).…”

Ultrasensitive, Multiplexed Buoyant Sensor for Monitoring Cytokines in Biofluids

“…We designed and printed antibody microarrays to achieve the multiplexed quantification of cytokine targets. Droplet jetting is a powerful printing approach to pattern different functional materials on various substrates. , Figure a shows a microdot array design with asymmetric spatial control markers to determine the location of each microdot for quantification. We printed the IL-6 capture antibody microarray on the PS surface to characterize and optimize the sensor performance.…”