Developing Gold Nanoparticles-Conjugated Aflatoxin B1 Antifungal Strips

Abstract

Lateral flow immunochromatographic assays are a powerful diagnostic tool for point-of-care tests, based on their simplicity, specificity, and sensitivity. In this study, a rapid and sensitive gold nanoparticle (AuNP) immunochromatographic strip is produced for detecting aflatoxin B1 (AFB1) in suspicious fungi-contaminated food samples. The 10 nm AuNPs were encompassed by bovine serum albumin (BSA) and AFB1 antibody. Thin-layer chromatography, gel electrophoresis and nuclear magnetic resonance spectroscopy were employed for analysing the chemical complexes. Various concentrations of AFB1 antigen (0-16 ng/mL) were tested with AFB1 antibody-BSA-AuNPs (conjugated AuNPs) and then analysed by scanning electron microscopy, ultraviolet-visible spectroscopy, and Zetasizer. The results showed that the AFB1 antibody was coupled to BSA by the N-hydroxysuccinimide ester method. The AuNPs application has the potential to contribute to AFB1 detection by monitoring a visible colour change from red to purple-blue, with a detection limit of 2 ng/mL in a 96-well plate. The lateral flow immunochromatographic strip tests are rapid, taking less than 10 min., and they have a detection capacity of 10 ng/g. The smartphone analysis of strips provided the results in 3 s, with a detection limit of 0.3 ng/g for AFB1 when the concentration was below 10 ng/g. Excellent agreement was found with AFB1 determination by high-performance liquid chromatography in the determination of AFB1 among 20 samples of peanuts, corn, rice, and bread.for Aflatoixin B1 (AFB1) [8]. The European Economic Community (EEC) has established permitted food contamination limits of 2 µg/kg for AFB1 and 4 µg/kg for the total concentration of the four AFLs since 1 February 1999 [9]. Therefore, it is necessary to develop strategies for achieving the limits of AFL contamination and reducing AFL exposure in vulnerable populations [10].Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) are the most popular techniques for detecting AFLs. However, these methods require extensive sample preparation, expensive instruments, and operation by skilled professionals. Alternatively, the enzyme-linked immunosorbent assay (ELISA) has been successfully developed for AFLs [11], but ELISA also needs incubation and washing steps, and application is mainly confined to laboratories. Lateral flow immunochromatographic/immunoassay strips (LFIAs) have received increasing attention for qualitative and quantitative analysis in different scientific sectors [12], including food safety, environmental monitoring, and precision medicine [12,13]. In 2005, Delmulle et al. [14] developed an LFIA for the detection of aflatoxin B1 (AFB1) in pig feed. Liao and Li [15] have made significant effort to investigate the effect of the core-shell silver-gold nanocomposites on the properties of LFIAs. However, this detection can only provide either qualitative (positive or negative) or semi-quantitative information on analyte concentration, and thereby does not satisfy the requirements for...

Aflatoxin Contamination: An Overview on Health Issues, Detection and Management Strategies

“…This technique could detect AFM1 at concentrations ranging from 0.01 to 1 g/L. Sojinrin and colleagues (2019) developed a rapid and sensitive gold nanoparticle (AuNP) immunochromatographic strip to detect AFB1 in peanuts, corn, rice, and bread samples [52]. The researchers used novel AuNPs-conjugated AFB1 antibody derivatives to develop a colorimetric assay in 96-well plates and lateral flow immunochromatographic assays (LFIAs) strips.…”

Development and Validation of an Automated Magneto-Controlled Pretreatment for Chromatography-Free Detection of Aflatoxin B1 in Cereals and Oils through Atomic Absorption Spectroscopy

“…In addition, chromatography also requires consuming some chromatographic consumables, such as chromatographic columns, etc. These limitations are overcome by fast detection methods, such as thin-layer chromatography [ 17 , 18 , 19 , 20 , 21 ], colloidal gold immunochromatography [ 22 , 23 , 24 , 25 ], and enzyme-linked immunosorbent assay [ 26 , 27 , 28 ]; these are commonly used in the routine monitoring of AFB 1 , especially for on-site or field detection, because of their low cost and convenience of operation. However, because limited sample clean-up strategies are used, the fast detection methods are often affected by matrix effects, leading to false-positive/negative results.…”

Development of a Lateral Flow Strip with a Positive Readout for the On-Site Detection of Aflatoxin B1

“…In 2005, Delmulle et al prepared an LFA strip using colloidal gold as a signal marker for the rapid assay of AFB 1 [ 17 ]. Subsequently, there has been a significant increase in the number of studies based on colloidal gold LFA for the detection of AFB 1 [ 18 , 19 , 20 ]. Until 2014, Wang first reported the use of luminescent nanomaterials as signal amplifiers for the more sensitive detection of AFB 1 [ 21 ].…”