Selective, Sensitive, and Rapid Analysis with Lateral-Flow Assays Based on Antibody-Gated Dye-Delivery Systems: The Example of Triacetone Triperoxide

Abstract

[EN] Antibodygated MSNs that are loaded with a rhodamine dye and that can be used for the determination of the presence of peroxide-based explosive TATP with a lateral-flow fluorescence reader have been designed and prepared, thereby allowing for detection limits in the lower ppb range. The mechanism of the detection relies on a displacement of the antibody from the surface of the hybrid material because of highly affine antibody-TATP interactions, which release a much larger number of entrapped dye molecules from the pores than antibodies are displaced. The high selectivity of the antibody is retained in the gated material, thus allowing for a remarkable discrimination against H2O2. System design and optimization led to straightforward integration into a lateral-flow assay without further treatment or conditioning of the test strips while guaranteeing fast overall assay times of minus or equal 10 min. Moreover, besides showing a remarkable robustness, the inherent architecture of the assay relies on a single-step immunochemical reaction, that is, it can dispense with secondary (labeled) antibodies and enables ratiometric signal assessment in the presence of the analyte by simple comparison of the fluorescence signals in two zones. Because of the modularity of the approach, the concept is easily generalizable and applicable for many small-molecule analytes. For instance, assays can be imagined that contain various hybrids of S1-AB(n) type, for which each material capped with a certain antibody is loaded with a different dye, thus envisioning multiplexed analysis with such simple assays.