Bio-Active Free Direct Optical Sensing of Aflatoxin B1 and Ochratoxin A Using a Manganese Oxide Nano-System

• Published in: Frontiers in nanotechnology Vol. 2
• Main Authors: Singh, Avinash Kumar, Lakshmi, G. B. V. S., Dhiman, Tarun Kumar, Kaushik, Ajeet, Solanki, Pratima R.
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 05.03.2021
• Subjects: aflatoxin-B1; direct sensing; manganese oxide; nano-system; Ochratoxin-A; UV-visible spectroscopy
• ISSN: 2673-3013; 2673-3013
• DOI: 10.3389/fnano.2020.621681

Aflatoxins-B1 (AFB1) and Ochratoxin-A (OchA) are the two types of major mycotoxin produced by Aspergillus flavus , Aspergillus parasiticus fungi, Aspergillus carbonarius, Aspergillus niger, and Penicillium verrocusumv . These toxins are mainly found in metabolite cereals, corn, coffee beans, and other oil-containing food items. Excessive consumption of these toxins can be carcinogenic and lead to cancer. Thus, their rapid testing became essential for food quality control. Herein, manganese oxide nanoparticles (MnO 2 nps) have been proposed to explore the interaction with AFB1 and OchA using UV-visible spectroscopy. MnO 2 nps were synthesized using the co-precipitation method. They were pure and crystalline with an average crystallite size of 5–6 nm. In the UV-vis study, the maximum absorbance for MnO 2 nps was observed around 260 nm. The maximum absorbance for AFB1 and OchA was observed at 365 and 380 nm, respectively, and its intensity enhanced with the addition of MnO 2 nps. Sequential changes were observed with varying the concentration of AFB1 and OchA with a fixed concentration of MnO 2 nps, resulting in proper interaction. The binding constant (k b ) and Gibbs free energy for MnO 2 nps-AFB1 and OchA were observed as 1.62 × 10 4  L g −1 and 2.67 × 10 4  L g −1 , and −24.002 and −25.256 kJ/mol, respectively. The limit of detection for AFB1 and OchA was measured as 4.08 and 10.84 ng/ml, respectively. This bio‐active free direct sensing approach of AFB1 and OchA sensing can be promoted as a potential analytical tool to estimate food quality rapidly and affordable manner at the point of use.