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Updated: Jul 31, 2025
Design and Development of Aptamer–Gold Nanoparticle Based Colorimetric Assays for In-the-field Applications
Published on: June 23, 2016
Screening of a High-Affinity Aptamer for Aflatoxin M1 and Development of Its Colorimetric Aptasensor
Xunjiao Wei1,2,3, Pengfei Ma1,2,3, Khan Imran Mahmood1,2,4
1State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Abstract:
Aflatoxin M1 (AFM1), a secondary metabolite of Aspergillus spp., is highly toxic and widely present in food matrices. Therefore, the detection of AFM1 is of great importance for the protection of food safety. In this study, a five-segment sequence was designed as the initial library. Graphene oxide-SELEX (GO-SELEX) was applied to screen AFM1. After seven rounds of repeated screening, affinity and specificity assays showed that aptamer 9 was the best candidate for AFM1. The dissociation constant (Kd) of aptamer 9 was 109.10 ± 6.02 nM. To verify the efficiency and sensitivity aptamer for the detection of AFM1, a colorimetric sensor based on the aptamer was constructed. The biosensor showed good linearity in the range of AFM1 concentration of 0.5-500.0 ng/mL with a detection limit of 0.50 ng/mL. This colorimetric method was successfully used for the detection of AFM1 in milk powder samples. Its detection recovery was 92.8-105.2%. This study was conducted to provide a reference for the detection of AFM1 in food.
Insights
Aflatoxin M1 (AFM1) detection is crucial for food safety. This study developed a sensitive aptamer-based colorimetric sensor for AFM1 in milk powder, achieving high accuracy and a low detection limit.
Area of Science:
- Food Science
- Analytical Chemistry
- Biotechnology
Background:
- Aflatoxin M1 (AFM1) is a toxic food contaminant requiring reliable detection methods.
- Ensuring food safety necessitates accurate quantification of AFM1 in various food matrices.
Purpose of the Study:
- To develop and validate a novel aptamer-based sensor for sensitive AFM1 detection.
- To establish a rapid and efficient colorimetric method for AFM1 quantification in food products.
Main Methods:
- Systematic Evolution of Ligands by Exponential Enrichment (SELEX) using graphene oxide (GO-SELEX) to screen AFM1 aptamers.
- Construction and characterization of a colorimetric biosensor utilizing the selected aptamer.
- Validation of the biosensor using spiked milk powder samples.
Main Results:
- Aptamer 9 demonstrated high affinity and specificity for AFM1, with a dissociation constant (Kd) of 109.10 ± 6.02 nM.
- The developed colorimetric biosensor exhibited linearity from 0.5-500.0 ng/mL with a detection limit of 0.50 ng/mL.
- Successful application in milk powder samples with high recovery rates (92.8-105.2%).
Conclusions:
- The aptamer-based colorimetric sensor offers a sensitive and reliable method for AFM1 detection in food.
- This approach provides a valuable tool for food safety monitoring and regulatory compliance.
- Further research can explore its application in other food matrices and for different mycotoxins.
