Multifunctional Nanoprobe-Amplified Enzyme-Linked Immunosorbent Assay on Capillary: A Universal Platform for Simple, Rapid, and Ultrasensitive Dual-Mode Pathogen Detection

Abstract

Although the traditional enzyme-linked immunosorbent assay (ELISA) has been widely applied in pathogen detection and clinical diagnostics, it always suffers from complex procedures, a long incubation time, unsatisfying sensitivity, and a single signal readout. Here, we developed a simple, rapid, and ultrasensitive platform for dual-mode pathogen detection based on a multifunctional nanoprobe integrated with a capillary ELISA (CLISA) platform. The novel capture antibodies-modified capillaries can act as a swab to combine in situ trace sampling and detection procedures, eliminating the dissociation between sampling and detection in traditional ELISA assays. With excellent photothermal and peroxidase-like activity, the Fe3O4@MoS2 nanoprobe with a unique p–n heterojunction was chosen as an enzyme substitute and amplified signal tag to label the detection antibody for further sandwich immune sensing. As the analyte concentration increased, the Fe3O4@MoS2 probe could generate dual-mode signals, including remarkable color changes from the chromogenic substrate oxidation as well as photothermal enhancement. Moreover, to avoid false negative results, the excellent magnetic capability of the Fe3O4@MoS2 probe can be used to pre-enrich the trace analytes, amplifying the detection signal and enhancing the immunoassay’s sensitivity. Under optimal conditions, specific and rapid detection of SARS-CoV-2 has been realized successfully based on this integrated nanoprobe-enhanced CLISA platform. The detection limits were 5.41 pg·mL–1 for the photothermal assay and 150 pg·mL–1 for the visual colorimetric assay. More importantly, the simple, affordable, and portable platform can also be expanded to rapidly detect other targets such as Staphylococcus aureus and Salmonella typhimurium in practical samples, making it a universal and attractive tool for multiple pathogen analysis and clinical testing in the post COVID-19 era.

Multi-modal nanoprobe-enabled biosensing platforms: a critical review

“…Molybdenum disulfide (MoS 2 ) has high electron transfer and catalytic efficiency, and is easily modified. Jiao et al 62 used the amplified photothermal colorimetric signal output of the Fe 3 O 4 @MoS 2 probe to achieve rapid qualitative and quantitative detection of a variety of pathogens. The combination of Au NPs and Fe 3 O 4 NPs is also often used in the design of multi-modal probes, which can simultaneously exhibit excellent surface chemical properties, special optical properties and superparamagnetic properties.…”

“Three-in-One” Multifunctional Hollow Nanocages with Colorimetric Photothermal Catalytic Activity for Enhancing Sensitivity in Biosensing

“…However, the development of this AuNP-ICA in the field of low-concentration target detection is hampered by the single signal output, which usually relies on colorimetric indicators and is difficult to distinguish due to subtle differences in color signals when analyzing low-concentration targets . To overcome this inherent constraint, various composite nanoparticles have been designed with capabilities such as fluorescence, photothermal, magnetic, , electrochemical signal, , and catalysis signals . These emerging signal tags aim to achieve multisignal output and enable a multimodal complementary analysis approach .…”

Nanoenzyme Hydrogel Film-Based Portable Point-of-Care Testing Platform for Double-Signal Visual Detection of PSA

“…However, these techniques are encumbered by complexities, high costs, and suboptimal user-friendliness. Mitigating these challenges can be achieved through the development of innovative sensing platforms utilizing commercial accessories or consumables such as test strips, capillary tubes, Eppendorf (EP) tubes, pipet tips, and so on. Thereinto, characterized by their affordability, accessibility, convenience, reliability, and user-friendly nature, EP tubes have shown significant potential as tools for constructing POCT platforms.…”