Ultrasensitive and Specific Detection of Salbutamol in Swine Feed, Meat, and Urine Samples by a Competitive Immunochromatographic Test Integrated with Surface-Enhanced Raman Scattering

Abstract

Salbutamol (SAL), a kind of β-agonist which can enhance the lean meat-to-fat ratio, has been inhibited as an additive used in animal feeds for livestock production in many countries due to its harmful effect to the consumers. In this study, an ultrasensitive and specific competitive immunochromatographic test (ICT) integrated with surfaceenhanced Raman scattering (SERS) for the detection of SAL was described. The immunoprobe was prepared by immobilizing polyclonal antibody against SAL on the surface of Au@Ag nanoparticles in which the Raman reporter (4-mercaptobenzoic acid, MBA) had been sandwiched. After ICT procedures, the specific SERS signals generated from MBA on the test line of the ICT strip were measured for the quantitative determination of SAL. The assay was completed in 15 min. The IC 50 and the limit of detection (LOD) values of the assay for SAL were 0.028 ng mL −1 and 3.0 pg mL −1 , respectively. There was no cross-reactivity (CR) of the assay with other three β-agonists (clenbuterol, phenylethanolamine A, and ractopamine), showing high specificity of the assay. Spiking experiments indicated that the average recoveries (n = 3) of SAL from swine feed, meat, and urine samples were in ranges of 98.4-105.2 % with the relative standard deviations (RSDs) of 1.7-7.8 %. The results demonstrated that the proposed ICT was a feasible method for ultrasensitive and specific detection SAL in swine feed, meat and urine samples, and could be extended for the detection of other target analytes.

Recent development of surface-enhanced Raman scattering for biosensing

“…Although the antibodies have the same structure conformation, the binding region is various for different antigen. The binding between antibody and antigen is due to hydrophobic interaction, hydrogen bonds, van der Waals forces, and ionic bonds [ 59 ]. Due to the lack of specificity and selectivity, traditional SERS substrates are not suitable for practical detection in complex matrices.…”

Tailoring noble metal nanoparticle designs to enable sensitive lateral flow immunoassay

“…These characteristics make core-shell nanostructures an ideal option for manufacturing high-performance SERS nanotags. Since its first discovery in 2007, coreshell SERS nanoprobes have attracted considerable attention and extensive research [169]. Given the excellent stability and monodispersity of gold and high enhancement effect of silver, AgNPs@Au-shell [170], AuNPs@Au-shell [171], and AuNPs@Ag-shell [172] SERS nanoprobes have been reported.…”

“…As an improvement, Li et al synthesized AuNPs@Ag-shell SERS nanoprobes (Au MBA @Ag) by embedding the Raman reporters (4-mercaptobenzoic acid, MBA) in the junction between the core and the shell, which can effectively protect the Raman molecules from the interference of environmental factors and possible leakage and degradation [173]. Subsequently, several similar AuNPs@Ag-shell SERS nanotags have been developed for the improved LFIA detection of salbutamol [169] and bacteria [174]. In addition, the metal shell number of core-shell nanostructures is increased to enhance the SERS performance.…”

An azo-coupling reaction-based surface enhanced resonance Raman scattering approach for ultrasensitive detection of salbutamol

“…S1 † ). To date, several indirect methods such as lateral flow immunochromatographic assay, 20 competitive immunochromatographic test 24 and competitive immunoassay, 25 combined with highly sensitive SERS have been developed to detect SAL. However, these immunochemical methods require complicated preparation of antibody, are costly, and especially, the determination conditions are highly strict.…”