Karan Saxena

Enhancing Sensitivity of Lateral Flow Immunoassays with Oxidative Coupling-Based Chromogenic Substrates for Horseradish Peroxidase

This work describes a novel approach to enhance the sensitivity of lateral flow immunoassays (LFIAs), which are commonly used in point-of-care diagnostics. We have developed novel oxidative coupling-based chromogenic substrates for horseradish peroxidase (HRP) enhancement of LFIA sensitivity. These substrates are inspired by the chemistry of commercial hair dyes consisting of two components: a primary intermediate and a colour developer that undergo an oxidative coupling reaction in the presence of HRP and hydrogen peroxide to generate an intensely coloured, precipitating dye. The LFIAs employing these substrates outperform conventional substrates and achieve an unprecedented sub-ng/mL limit of detection for Human IgG. The new substrates offer substantial cost savings compared to the commercially available gold nanoparticle-based LFAs, making them a compelling choice for point-of-care diagnostics. We have demonstrated the use of these substrates in detecting Human IgG as a model analyte, and the results indicate that LFIAs employing these substrates can detect Human IgG at 0.2 ng/mL, significantly surpassing reported sensitivities in the literature.

This study provides a promising alternative to conventional substrates and has the potential to improve the sensitivity of LFAs in point-of-care diagnostics.