Preparation of arsenic(iii) monoclonal antibodies and preliminary evaluation of a novel silver-coated gold nanorod SERS immunoassay strip construction

Abstract

Heavy metal pollution has become a growing concern in industrial, agricultural, and manufacturing processes, posing a significant threat to human health. Among these heavy metals, arsenic (As) is highly toxic and shares similar chemical properties and environmental behavior with other heavy metals. As(III) is particularly toxic compared to other forms of arsenic. Therefore, it is essential to develop a real-time, rapid, and sensitive method for the determination of As(III). In this study, we employed a unique bifunctional chelator, 1-(4-isothiocyanobenzyl)-ethylenediamine N,N,N′,N′-tetraacetic acid (ITCBE), to prepare a complete antigen. Through a series of tests including balb/c mouse immunization, cell fusion (mouse L2041 spleen cells with mouse myeloma cells SP2/0), and subcloning, we generated four monoclonal cell lines (1C1, 2C2, 3A9, and 4A11). These cell lines demonstrated high purity, high affinity, and IC₅₀ values of less than 50 μg mL⁻¹. Monoclonal antibody 4A11, which exhibited a strong Raman signal, was selected as the probe, and Au@Ag 200 was utilized as the surface-enhanced Raman scattering (SERS) substrate for the preliminary establishment of SERS immunochromatographic test strips. The sensitivity of the SERS immunochromatographic test strips, measured through Raman signal detection, showed a significant improvement compared to the SERS immunochromatographic test strips analyzed by colorimetry (LOD = 49.43 μg mL⁻¹ and LDR = 5.32–81.31 μg mL⁻¹). The SERS immunochromatographic test strips achieved a LOD of 7.62 μg mL⁻¹ and an LDR of 12.66–71.84 μg mL⁻¹. This study presents innovative methodologies for the rapid detection of As(III) using SERS immunochromatographic test strips.