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

Abstract

Aflatoxin B1 is one of the contamination indicators for food safety monitoring. The rapid and effective assessment and determination of AFB1 in food is of great importance to dietary safety. The lateral flow assay shows advantages in its simplicity, and rapidity, and provides a visual readout, while the available lateral flow assay for AFB1 requires a competitive format that produces readings inversely proportional to the AFB1 concentration, which is counterintuitive and may lead to a potential misinterpretation of the results. Herein, we developed a positive readout aptamer-based lateral flow strip (Apt-strip) for the detection of AFB1. This Apt-strip relies on the competition between AFB1 and fluorescein-labeled complementary DNA strands (FAM-cDNA) for affinity binding to limited aptamers against AFB1 (AFB1-Apt). In the absence of AFB1, AFB1-Apt hybridizes with FAM-cDNA. No signal at the T-line of the Apt-strip was observed. In contrast, AFB1-Apt binds to AFB1 in the sample, and then a part of the FAM-cDNA is hybridized with the free AFB1-Apt, at which time the other unreacted FAM-cDNA is captured by A35-Apt on the T-line. The signal was observed. This method achieved fast detection of AFB1 with a detection limit (DL) of 0.1 ng/mL, positive readout, and increased sensitivity.

Direct Detection of Viral Infections from Swab Samples by Probe‐Gated Silica Nanoparticle‐Based Lateral Flow Assay

“…Fluorescence signal molecules are the strongest reporter molecule in the LFA system with a sharp distinction between excitation and emission wavelength. Fluorescein could be used in the LFA system as a labeling molecule like FITC and a direct detection molecule like releasing a reporter [28,41,47,48] . These systems rely on FITC signaling with a target analyte reaction in TL or CL.…”

“…Fluorescein could be used in the LFA system as a labeling molecule like FITC and a direct detection molecule like releasing a reporter. [28,41,47,48] These systems rely on FITC signaling with a target analyte reaction in TL or CL. Moreover, the rhodamine B molecule gives a detectable signal in the LFA system, especially for polymersomes with a high encapsulation efficiency.…”

Improvement of the sensitivity of lateral flow systems for detecting mycotoxins: Up‐to‐date strategies and future perspectives

“…The International Agency for Research on Cancer (IARC) has classified aflatoxins (AFs) as group 1 carcinogens, fumonisins (FBs) and ochratoxin A (OTA) as group 2B carcinogens, and zearalenone (ZEN), deoxynivalenol (DON), T‐2 toxin (T‐2), and patulin as group 3 probable carcinogens (Abdolmaleki et al., 2021; IARC, 2012). AFs mainly include aflatoxin B 1 (AFB 1 ), aflatoxin B 2 (AFB 2 ), aflatoxin G 1 , aflatoxin G 2 , and aflatoxin M 1 (AFM 1 ) (Shen et al., 2022). In addition to carcinogenic and mutagenic properties, they also inhibit the activity of the immune system and cause damage to internal organs (Da Silva et al., 2021; Turna et al., 2023).…”