Hierarchical Nanogold Labels to Improve the Sensitivity of Lateral Flow Immunoassay

Abstract

Lateral flow immunoassay (LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation. However, an LFIA based on gold nanospheres lacks the desired sensitivity, thereby limiting its wide applications. In this study, spherical nanogold labels along with new types of nanogold labels such as gold nanopopcorns and nanostars were prepared, characterized, and applied for LFIA of model protein antigen procalcitonin. It was found that the label with a structure close to spherical provided more uniform distribution of specific antibodies on its surface, indicative of its suitability for this type of analysis. LFIA using gold nanopopcorns as a label allowed procalcitonin detection over a linear range of 0.5–10 ng mL−1 with the limit of detection of 0.1 ng mL−1, which was fivefold higher than the sensitivity of the assay with gold nanospheres. Another approach to improve the sensitivity of the assay included the silver enhancement method, which was used to compare the amplification of LFIA for procalcitonin detection. The sensitivity of procalcitonin determination by this method was 10 times better the sensitivity of the conventional LFIA with gold nanosphere as a label. The proposed approach of LFIA based on gold nanopopcorns improved the detection sensitivity without additional steps and prevented the increased consumption of specific reagents (antibodies).

Compact Magneto‐Fluorescent Colloids by Hierarchical Assembly of Dual‐Components in Radial Channels for Sensitive Point‐of‐Care Immunoassay

“…Therefore, the SIQS‐based LFIA provides flexible dual‐modal signal readouts for personalized quantification scenarios and the potential for self‐validating to exclude background interferences. [ 62–65 ] Compared with previous reports for PCT detection, the SIQS‐based LFIA exhibits high sensitivity and relatively short detection time (Table S2, Supporting Information), [ 66–73 ] demonstrating the potential of the proposed assay for POC detecting of PCT.…”

Rapid point‐of‐care testing methods/devices for meat species identification: A review

“…Recently, different morphological forms of nanogold have also been studied as detection tags. A significant increase in the sensitivity of detection has been found when gold nanopopcorns and nanocages have been used in place of AuNPs (Serebrennikova, Samsonova, & Osipov, 2017; Yang, Ozsoz, & Liu, 2017). The application of gold nanoflowers (AuNFs) increases the sensitivity of LFA detection in comparison to the gold nanospheres‐based LFA assay (Di Nardo, Baggiani, Giovannoli, Spano, & Anfossi, 2017; Lai et al., 2019; Petrakova, Urusov, Zherdev, & Dzantiev, 2019).…”

Integrating high-performing electrochemical transducers in lateral flow assay

“…Further improvements focused on tracer strategies, like metal ligand complexes [17], cellulose nanobeads [18], and the coupling to a smartphone [19]. In the past few years, the research has been focused on further developing labels like Ptnanoparticles (PtNP) [20], the use of Ag staining for amplification [21], combining LFA with SERS [22], implementing nanofibers (NF) [23], using different shapes of colloidal gold [24], using different nanoparticles (NP) like IrO 2 [25] or CuO [26], and integrating electrodes for electrochemiluminescence (ECL) [27]. The texts shown in blue, green, purple, and red represent the development focusing on assay format, signal tracer, detection technique, and recognition element, respectively.…”