Nanomaterial and Interface Advances in Immunoassay Biosensors

Abstract

Biosensors have been used for a remarkable array of applications, including infectious diseases, environmental monitoring, cancer diagnosis, food safety, and numerous others. In particular, the global COVID-19 pandemic has exposed a need for rapid tests, so the type of biosensor that has gained considerable interest recently is immunoassays, which are used for rapid diagnostics. The performance of paper-based lateral flow and dipstick immunoassays is influenced by the physical properties of the nanoparticles (NPs), NP−antibody conjugates, and paper substrate. Many materials innovations have enhanced diagnostics by increasing the sensitivity or enabling unique readouts. However, negative side effects can arise at the interface between the biological sample and biomolecules and the NP or paper substrate, such as nonspecific adsorption and protein denaturation. In this Perspective, we discuss the immunoassay components and highlight chemistry and materials innovations that can improve sensitivity. We also explore the range of biointerface issues that can present challenges for immunoassays.

Gold Nanoparticle Paper Immunoassays for Sensing the Presence of Vibrio parahaemolyticus in Oyster Hemolymph

“…The variability for the test in hemolymph has a standard deviation on the order of 23–35%, and while test precision is much less compared to commercial assays for other antigens, we believe some of this can be attributed to the challenging sample matrix of the hemolymph, which has a high salinity and thus prone to inducing NP aggregation. 40 , 45 …”

“…The variability for the test in hemolymph has a standard deviation on the order of 23−35%, and while test precision is much less compared to commercial assays for other antigens, we believe some of this can be attributed to the challenging sample matrix of the hemolymph, which has a high salinity and thus prone to inducing NP aggregation. 40,45 Isolation of Negative Controls from Hemolymph. Hemolymph contains a wide variety of bacteria 46 that may result in false positives in the present test.…”

Amplification and extraction free quantitative detection of viral nucleic acids and single-base mismatches using magnetic signal amplification circuit

“…Current clustering-based MIAs have reached the LOD in low nM range for detection of DNA 54 and viral proteins, 55 yet insufficient for testing clinical samples. Unlike other immunoassays, 56 to reach the desired sensitivity, adaptability, and specificity that can push the MIAs towards clinical applications, we developed a facile declustering-based MIAs; where magnetic clusters dissociate into MNPs in presence of target nucleic acids. Therefore, unspecific clustering of nanoparticles does not interfere with the assay result (Fig.…”

An approach to use machine learning to optimize paper immunoassays for SARS-CoV-2 IgG and IgM antibodies

“…5,6 These conditions are ripe for nonspecific adsorption, protein corona formation, and NP precipitation, 7 which can ultimately cause both false positives and false negatives, confounding test results. [8][9][10] Optimization of the nano-bio interface requires varying the NP synthesis protocol, surfactant types, and bioconjugation chemistries.…”